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Sample records for blood measurement method

  1. Noninvasive methods of measuring bone blood perfusion

    OpenAIRE

    Dyke, J. P.; Aaron, R.K.

    2010-01-01

    Measurement of bone blood flow and perfusion characteristics in a noninvasive and serial manner would be advantageous in assessing revascularization after trauma and the possible risk of avascular necrosis. Many disease states, including osteoporosis, osteoarthritis, and bone neoplasms, result in disturbed bone perfusion. A causal link between bone perfusion and remodeling has shown its importance in sustained healing and regrowth following injury. Measurement of perfusion and permeability wi...

  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. Methods for blood flow measurements using ultrasound contrast agents

    Science.gov (United States)

    Fowlkes, J. Brian

    2003-10-01

    Blood flow measurements using ultrasound contrast agents are being investigated for myocardial perfusion and more recently in other organ systems. The methods are based largely on the relative increase in echogenicity due to the concentration of bubbles present in the ultrasound beam. In the simplest form, regional differences in blood volume can be inferred but the possibility exists to extract perfusion from the transit of contrast agent through tissue. Perfusion measurements rely on determining the flux of blood through a tissue volume and as such require knowledge of the fractional blood volume (FBV), i.e., ml blood/g tissue and the rate of exchange, commonly measured as the mean transit time (MTT). This presentation will discuss methods of determining each of these values and their combination to estimate tissue perfusion. Underlying principles of indicator-dilution theory will be provided in the context of ultrasound contrast agents. Current methods for determining MTT will include imaging of the intravenous bolus, in-plane contrast disruption with interval and real-time contrast recovery imaging, and control of contrast agent flow using arterial disruption (contrast interruption). The advantages and limitations of the methods will be examined along with current applications. [Work supported in part by NIH.

  4. Methods for measurement of cerebral blood flow in man

    DEFF Research Database (Denmark)

    Lassen, N A

    1976-01-01

    A survey of the currently available methods for the measurement of cerebral blood flow in man is given. Many of the clinically important brain diseases such as tumors, stroke, brain trauma or epilepsy entail focal or regional flow alterations. Therefore a special emphasis is placed on methods...... information both on spatial localization and, especially, on ischemic areas. The most promising is computer-assisted axial tomography with freely diffusible radioactive isotopes or with x-rays using an intra-arterial injection of contrast. But, the available techniques are still too slow: in order to measure...

  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. 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...

  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. 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.

  10. 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 ...

  11. A Surface Heat Disturbance Method for Measuring Local TIssue Blood Perfusion Rate

    Institute of Scientific and Technical Information of China (English)

    PengJianshu; TianYongquan

    1996-01-01

    A non-damage method for measuring local tissue blood perfusion rate by surface heat disturbance and its two special embodiments for realizing this measurement are presented in this paper,In the derivation of mathematical model,the Pennes equation is used,and two parameters which are very diffcult to be known-the arterial blood temperature Ta and the metabolic heat generation rate qm,have been eliminated.So if has provided a feasible basis for application.In this paper,the performance and the adaptable condition of the measurement method and its structure peculiarities are discussed over a wide variety of parameters.Moreover,the effectiveness of the measurement method has been demonstrated by means of the quantitative measurement of tissue in vitro,the comparative measurement of animal under artificial perfusion and the dependence measurement in human body.

  12. 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.

  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. [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

  16. 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)

  17. 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

  18. 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.)

  19. 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.

  20. 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 ...

  1. [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

  2. 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 ...

  3. 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...... of 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....

  4. Investigation of electrolyte measurement in diluted whole blood using spectroscopic and chemometric methods

    Science.gov (United States)

    Soller, Babs R.; Favreau, Janice; Idwasi, Patrick O.

    2003-01-01

    The feasibility of using near-infrared (NIR) spectroscopy in combination with partial least-squares (PLS) regression was explored to measure electrolyte concentration in whole blood samples. Spectra were collected from diluted blood samples containing randomized, clinically relevant concentrations of Na+, K+, and Ca2+. Sodium was also studied in lysed blood. Reference measurements were made from the same samples using a standard clinical chemistry instrument. Partial least squares (PLS) was used to develop calibration models for each ion with acceptable results (Na+, R2 = 0.86, CVSEP = 9.5 mmol/L; K+, R2 = 0.54, CVSEP = 1.4 mmol/L; Ca2+, R2 = 0.56, CVSEP = 0.18 mmol/L). Slightly improved results were obtained using a narrower wavelength region (470-925 nm) where hemoglobin, but not water, absorbed indicating that ionic interaction with hemoglobin is as effective as water in causing measurable spectral variation. Good models were also achieved for sodium in lysed blood, illustrating that cell swelling, which is correlated with sodium concentration, is not required for calibration model development.

  5. 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.

  6. 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

  7. 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

  8. Measurement of blood-brain barrier permeability using dynamic Gd-DTPA scanning--a comparison of methods

    DEFF Research Database (Denmark)

    Larsson, H B; Tofts, P S

    1992-01-01

    Two recently published methods of blood-brain barrier permeability measurement using Gd-DTPA scanning are compared by authors representing each group. The physiological models are reconciled. Results from both groups agree. These show that the transfer constant (the permeability surface area prod...

  9. 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.

  10. 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)

  11. 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.

  12. 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.)

  13. 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)

  14. A new method for blood velocity measurements using ultrasound FMCW signals.

    Science.gov (United States)

    Kunita, Masanori; Sudo, Masamitsu; Inoue, Shinya; Akahane, Mutsuhiro

    2010-05-01

    The low peak power of frequency-modulated continuous wave (FMCW) radar makes it attractive for various applications, including vehicle collision warning systems and airborne radio altimeters. This paper describes a new ultrasound Doppler measurement system that measures blood flow velocity based on principles similar to those of FMCW radar. We propose a sinusoidal wave for FM modulation and introduce a new demodulation technique for obtaining Doppler information with high SNR and range resolution. Doppler signals are demodulated with a reference FMCW signal to adjust delay times so that they are equal to propagation times between the transmitter and the receiver. Analytical results suggest that Doppler signals can be obtained from a selected position, as with a sample volume in pulse wave Doppler systems, and that the resulting SNR is nearly identical to that obtained with continuous wave (CW) Doppler systems. Additionally, clutter power is less than that of CW Doppler systems. The analytical results were verified by experiments involving electronic circuits and Doppler ultrasound phantoms. PMID:20442017

  15. Study of Estimation Method for Unsteady Inflow Velocity in Two-Dimensional Ultrasonic-Measurement-Integrated Blood Flow Simulation.

    Science.gov (United States)

    Kadowaki, Hiroko; Hayase, Toshiyuki; Funamoto, Kenichi; Taniguchi, Nobuyuki

    2016-02-01

    Information on hemodynamics is essential for elucidation of mechanisms and development of novel diagnostic methods for circulatory diseases. Two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation can correctly reproduce an intravascular blood flow field and hemodynamics by feeding back an ultrasonic measurement to the numerical blood flow simulation. In this method, it is critically important to give the correct cross-sectional average inflow velocity (inflow velocity) as the boundary condition. However, systematic study has not been done on the relative validity and effectiveness of existing inflow velocity estimation methods for various target flow fields. The aim of this study was to examine the existing methods systematically and to establish a method to accurately estimate inflow velocities for various vessel geometries and flow conditions in 2D-UMI simulations. A numerical experiment was performed for 2D-UMI simulation of blood flow models in a straight vessel with inflow velocity profiles symmetric and asymmetric to the vessel axis using existing evaluation functions based on Doppler velocity error for the inflow velocity estimation. As a result, it was clarified that a significantly large estimation error occurs in the asymmetric flow due to a nonfeedback domain near the downstream end of the calculation domain. Hence, a new inflow velocity estimation method of 2D-UMI simulation is proposed in which the feedback and evaluation domains are extended to the downstream end. Further numerical experiments of 2D-UMI simulation for two realistic vessel geometries of a healthy blood vessel and a stenosed one confirmed the effectiveness of the proposed method. PMID:26241967

  16. 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;

    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......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 infarcts involving cortical surface structures were included in the study. Eleven such patients were found among 43 consecutive patients with completed stroke, all investigated with CT-scan. The blood supply to the infarcted areas was evaluated using 3 different approaches: 1) The first minute washout...... ischemic lesions. The method should be limited to the qualitative demonstration of the ischemic lesions for which it is fully reliable....

  17. 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)

  18. A rapid liquid chromatography tandem mass spectrometry-based method for measuring propranolol on dried blood spots.

    Science.gov (United States)

    Della Bona, Maria Luisa; Malvagia, Sabrina; Villanelli, Fabio; Giocaliere, Elisa; Ombrone, Daniela; Funghini, Silvia; Filippi, Luca; Cavallaro, Giacomo; Bagnoli, Paola; Guerrini, Renzo; la Marca, Giancarlo

    2013-05-01

    Propranolol, a non-selective beta blocker drug, is used in young infants and newborns for treating several heart diseases; its pharmacokinetics has been extensively evaluated in adult patients using extrapolation to treat pediatric population. The purpose of the present study was to develop and validate a method to measure propranolol levels in dried blood spots. The analysis was performed by using liquid chromatography/tandem mass spectrometry operating in multiple reaction monitoring mode. The calibration curve in matrix was linear in the concentration range of 2.5-200 μg/L with correlation coefficient r=0.9996. Intra-day and inter-day precisions and biases were less than 8.0% (n=10) and 11.5% (n=10) respectively. The recoveries ranged from 94 to 100% and the matrix effect did not result in a severe signal suppression. Propranolol on dried blood spot showed a good stability at three different temperatures for one month. This paper describes a micromethod for measuring propranolol levels on dried blood spot, which determines a great advantage in neonates or young infants during pharmacokinetic studies because of less invasive sampling and small blood volume required.

  19. 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

  20. 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.

  1. 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...

  2. 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

  3. Working meeting on blood pressure measurement: suggestions for measuring blood pressure to use in populations surveys.

    Science.gov (United States)

    2003-11-01

    As part of the Pan American Hypertension Initiative (PAHI), the Pan American Health Organization and the National Heart, Lung, and Blood Institute of the National Institutes of Health of the United States of America conducted a working meeting to discuss blood pressure (BP) measurement methods used in various hypertension prevalence surveys and clinical trials, with the objective of developing a BP measurement protocol for use in hypertension prevalence surveys in the Americas. No such common protocol has existed in the Americas, so it has been difficult to compare hypertension prevention and intervention strategies. This piece describes a proposed standard method for measuring blood pressure for use in population surveys in the Region of the Americas. The piece covers: considerations for developing a common blood pressure measurement protocol, critical issues in measuring blood pressure in national surveys, minimum procedures for blood pressure measurement during surveillance, and quality assessment of blood pressure.

  4. Patient-specific errors in agreement between International Normalized Ratios measured by a whole blood coagulometer and by a routine plasma-based method.

    Science.gov (United States)

    Attermann, Jørn; Andersen, Niels T; Korsgaard, Helle; Maegaard, Marianne; Hasenkam, J Michael

    2004-04-01

    We applied a new statistical method to improve comparisons between systems measuring prothrombin time (PT) by splitting disagreement into systematic errors, which can be eliminated, and random errors, which can not. We found that the disagreement between International Normalized Ratio (INR) measurements based on plasma and whole blood was significantly patient-dependent.

  5. 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

  6. 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.

  7. 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 ...

  8. 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

  9. 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 ...

  10. Progress and Clinical Application of PET Cerebral Blood Flow Measurement Method%PET脑血流量测量方法和临床应用进展

    Institute of Scientific and Technical Information of China (English)

    徐浩; 赵周社; 李红; 凌雪英; 唐勇进; 弓健; 郭斌

    2015-01-01

    Cerebral blood flow measurement for cerebrovascular disease,brain tumor diagnosis and therapeutic effect evaluation has important clinical value.PET is based on positron tracer technique for noninvasive,accurate measurement of cerebral blood flow is increasingly widely used in clinical.PET measurement of cerebral blood flow in accordance with the methods and use of positron tracer is different,and the measurement methods are divided into equilibrium method,autoradiographic method and dynamic method.15O-H2O tracer PET measurement of cerebral blood flow is considered to be the "gold standard" method of cerebral blood flow measurement.As the PET equipment resolution improving,the new image reconstruction method using PET and MRI image fusion technology continues to mature,the 18F-FDG first pass image using derivative arterial input function (IDAIF) replace artery blood sample accurate measurement of cerebral blood volume method has been paid attention to,may gradually replace the high cost of 15O-H2O measurement of cerebral blood flow.PET is noninvasive,convenient and accurate measurement of cerebral blood flow in clinical use will greatly promote cerebral vascular disease,brain tumor and brain degenerative disease early diagnosis,differential diagnosis and personalized medicine.This paper introduced PET cerebral blood flow measurement principle,methods and progress in clinical application.%脑血流量测量对于脑血管疾病、脑肿瘤诊断和疗效评估具有重要的临床价值.PET是基于正电子示剂技术无创性、精确测量脑血流量的方法,正日益广泛地应用于临床.按照PET测量脑血流量的方法和使用的正电子示踪剂不同,其测量方法分为平衡法、放射自显影法和动力学方法三种.18O-H2O示踪剂PET测量脑血流量被认为测量脑血流方法的“金标准”.随着PET设备分辨率提高、新的图像重建方法使用和PET与MRI图像融合技术不断成熟,18F-FDG首次通过、采用图

  11. 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.

  12. 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)

  13. Blood proteins analysis by Raman spectroscopy method

    Science.gov (United States)

    Artemyev, D. N.; Bratchenko, I. A.; Khristoforova, Yu. A.; Lykina, A. A.; Myakinin, O. O.; Kuzmina, T. P.; Davydkin, I. L.; Zakharov, V. P.

    2016-04-01

    This work is devoted to study the possibility of plasma proteins (albumin, globulins) concentration measurement using Raman spectroscopy setup. The blood plasma and whole blood were studied in this research. The obtained Raman spectra showed significant variation of intensities of certain spectral bands 940, 1005, 1330, 1450 and 1650 cm-1 for different protein fractions. Partial least squares regression analysis was used for determination of correlation coefficients. We have shown that the proposed method represents the structure and biochemical composition of major blood proteins.

  14. 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....

  15. 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.

  16. 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.

  17. 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...

  18. 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)

  19. Specific heat of rabbit blood measured by cooling method%冷却法测定家兔血液的比热

    Institute of Scientific and Technical Information of China (English)

    贾斌; 李建军; 温光楠

    2001-01-01

    目的 家兔血液比热是热稀释法测量家兔心输出量的重要修正系数.方法 根据牛顿冷却定律,采用同一容器盛装兔血或水,若两者温度与体积都基本相同,则水与兔血的散热规律基本相同,水的比热已知,便可求出兔血的比热;又利用同一系统测得标准100g·L-1NaCl溶液的比热值,求得测量系统误差,对所测兔血比热进行修正.结果 对测得的多组兔血比热数据进行合理筛选后,得到新鲜兔血测量值:0.886±0.022,经误差修正得到家兔血液比热:0.849±0.022;陈旧兔血测量值:1.020±0.021,经误差修正后:0.997±0.021.结论 冷却法测定家兔血液比热方法可靠,数据处理合理,结果可信.%AIM To determine specific heat of rabbit blood for calculatingcardiac output of rabbits by thermodilution. METHODS According to Newton's law of cooling, specific heat of rabbit blood was measured from that of water, by comparing the speed of temperature change of them measured respectively in the same system. The measured specific heat of rabbit blood was corrected with systematic error of specific heat of 100 g·L-1 NaCl solution measured in the same system. RESULTS Specific heat of fresh whole blood of rabbits was 0.886±0.022; After correction, 0.849±0.022; Blood after being stored, the specific heat changed, 1.020±0.021,and 0.997±0.021 after correction. CONCLUSION Corrected specific heat value of fresh blood is more reasonable, and the calculated cardiac output might be more accurate.

  20. 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

  1. 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.)

  2. 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)

  3. 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.

  4. 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.

  5. 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...

  6. 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

  7. Detection and measurement of retinal blood vessel pulsatile motion

    Science.gov (United States)

    Xiao, Di; Frost, Shaun; Vignarajan, Janardhan; An, Dong; Tay-Kearney, Mei-Ling; Kanagasingam, Yogi

    2016-03-01

    Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. Pulsatile properties caused by cardiac rhythm, such as spontaneous venous pulsation (SVP) and pulsatile motion of small arterioles, can be visualized by dynamic retinal imaging techniques and provide clinical significance. In this paper, we aim at vessel pulsatile motion detection and measurement. We proposed a novel approach for pulsatile motion measurement of retinal blood vessels by applying retinal image registration, blood vessel detection and blood vessel motion detection and measurement on infrared retinal image sequences. The performance of the proposed methods was evaluated on 8 image sequences with 240 images. A preliminary result has demonstrated the good performance of the method for blood vessel pulsatile motion observation and measurement.

  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. 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.

  11. 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

  12. Pitfalls in blood pressure measurement in daily practice

    NARCIS (Netherlands)

    Houweling, ST; Kleefstra, N; Lutgers, HL; Groenier, KH; Meyboom-de Jong, B; Bilo, HJG

    2006-01-01

    Background. Accurate blood pressure (BP) readings and correctly interpreting the obtained values are of great importance. However, there is considerable variation in the different BP measuring methods suggested in guidelines and used in hypertension trials. Objective. To compare the different method

  13. 基于光电容积脉搏波法血氧饱和度测量系统研究%A research of blood oxygen saturation measurement system based on the photoplethysmography method

    Institute of Scientific and Technical Information of China (English)

    苌飞霸; 陈维平; 徐力; 尹军

    2015-01-01

    血氧饱和度是人体一项重要的生理参数。目前,血氧饱和度检测方法分为有创血氧饱和度检测和基于光电容积脉搏波法的无创血氧饱和度检测。其中,基于光电容积脉搏波法的无创血氧饱和度研究模型采用人体光电容积脉搏波信号作为信息载体进行无创连续的血氧饱和度的检测。该文综述了基于血液容积波法无创血氧饱和度测量原理及测量系统;重点介绍了反射式血氧饱和度检测系统;并对影响血液容积波法无创血氧饱和度测量系统准确性的相关因素进行了归纳与总结。%The blood oxygen saturation is an important human physiological parameter .Currently, the blood oxygen saturation detection method is divided into the invasive measurement of blood oxygen satura -tion and noninvasive measurement of blood oxygen saturation based on photoplethysmography method .A-mong them , based on photoplethysmography method of noninvasive oxygen saturation research model a-dopts photoelectric volume pulse wave signals of the human body as an information carrier for noninvasive continuous blood oxygen saturation detection .This paper reviews noninvasive oxygen saturation based on photoplethysmography method measurement principle and measurement system , mainly introduces the re-flectance oxygen saturation detection system .And the related factors affecting the accuracy of the nonin-vasive blood oxygen saturation measurement system were concluded and summarized .

  14. 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.

  15. 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.

  16. Estimating the measurement uncertainty in forensic blood alcohol analysis.

    Science.gov (United States)

    Gullberg, Rod G

    2012-04-01

    For many reasons, forensic toxicologists are being asked to determine and report their measurement uncertainty in blood alcohol analysis. While understood conceptually, the elements and computations involved in determining measurement uncertainty are generally foreign to most forensic toxicologists. Several established and well-documented methods are available to determine and report the uncertainty in blood alcohol measurement. A straightforward bottom-up approach is presented that includes: (1) specifying the measurand, (2) identifying the major components of uncertainty, (3) quantifying the components, (4) statistically combining the components and (5) reporting the results. A hypothetical example is presented that employs reasonable estimates for forensic blood alcohol analysis assuming headspace gas chromatography. These computations are easily employed in spreadsheet programs as well. Determining and reporting measurement uncertainty is an important element in establishing fitness-for-purpose. Indeed, the demand for such computations and information from the forensic toxicologist will continue to increase.

  17. 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.

  18. 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....

  19. 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...

  20. 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.

  1. Randomized Comparison of the Therapeutic Effect of Acupuncture, Massage, and Tachibana-Style-Method on Stiff Shoulders by Measuring Muscle Firmness, VAS, Pulse, and Blood Pressure

    Directory of Open Access Journals (Sweden)

    Kazuhiro Tachibana

    2012-01-01

    Full Text Available To compare the therapeutic efficacy of acupuncture, massage, and Tachibana-Ryojutsu (one of Japanese traditional body balance therapy techniques (SEITAI, on stiff shoulders, the subjects’ muscle firmness, blood pressure, pulse, VAS, and body temperature were measured before and after the treatment. Forty-seven volunteer subjects gave written informed consent to participate in this study. The subjects were randomly divided into three groups to receive acupuncture, massage, or Tachibana-Ryojutsu. Each therapy lasted for 90 seconds. The acupuncture treatment was applied by a retaining-needle at GB-21, massage was conducted softly on the shoulders, and Tachibana-Ryojutsu treated only the muscles and joints from the legs to buttocks without touching the shoulders or backs. The study indicated that the muscle firmness and VAS of the Tachibana-Ryojutsu group decreased significantly in comparison with the acupuncture and massage groups after treatment.

  2. TREATMENT OF HYPERTENSION USING TELEMEDICAL HOME BLOOD PRESSURE MEASUREMENTS

    DEFF Research Database (Denmark)

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

    2015-01-01

    OBJECTIVE: Telemonitoring of home blood pressure measurements (TBPM) is a new and promising supplement to diagnosis, control and treatment of hypertension. We wanted to compare the outcome of antihypertensive treatment based on TBPM and conventional monitoring of blood pressure. DESIGN AND METHOD....../181), p = 0.34. Blood pressure reduction in the TBPM group varied with the different practices. CONCLUSIONS: No further reduction in ABPM or number of patients reaching blood pressure targets was observed when electronic transmission of TBPM was applied in the treatment of hypertension by GPs. Thus......: 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...

  3. 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.

  4. 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

  5. HbA1c measurements from dried blood spots : validation and patient satisfaction

    NARCIS (Netherlands)

    Fokkema, Margaretha; Bakker, Andries J; de Boer, Fokje; Kooistra, Jeltsje; de Vries, Sifra; Wolthuis, Albert

    2009-01-01

    Background: This study evaluates HbA1c measurements from dried blood spots collected on filter paper and compares HbA1c from filter paper (capillary blood) with HbA1c measured in venous blood. Methods: Patient satisfaction was evaluated using a questionnaire. The performance with the filter paper me

  6. [The landmarks of the measurement of cerebral blood flow].

    Science.gov (United States)

    István, Nyáry

    2008-01-30

    History of the measurement of local cerebral blood flow may cover a period of one and a half centuries. Parallel forthcoming of both theoretical and technical development were the key elements of ensuing progress resulting in the present state, when by the aid of in vivo blood flow and metabolic maps, we can visualize locales of brain functioning and their interconnections. Two theoretical landmarks should be mentioned in this historic process. First, the work of Adolf Fick, as the starter of quantitative measurements in this field, and Seymour Kety's model of a single, homogenously perfused tissue element. The solution of this model, in the form of Kety's equation is still fundamental to present day blood flow mapping techniques. Among the numerous investigators over the past years, two Hungarian scientist can be named as major contributors. Kálmán Sántha made substantial studies with continuous registration of local cerebral blood flow by the aid of thermocouples, while Emil P6sztor invented the hydrogen clearance method for the measurement of local cerebral blood flow both in human and in animal studies.

  7. Accurate blood flow measurements: are artificial tracers necessary?

    Directory of Open Access Journals (Sweden)

    Christian Poelma

    Full Text Available Imaging-based blood flow measurement techniques, such as particle image velocimetry, have become an important tool in cardiovascular research. They provide quantitative information about blood flow, which benefits applications ranging from developmental biology to tumor perfusion studies. Studies using these methods can be classified based on whether they use artificial tracers or red blood cells to visualize the fluid motion. We here present the first direct comparison in vivo of both methods. For high magnification cases, the experiments using red blood cells strongly underestimate the flow (up to 50% in the present case, as compared to the tracer results. For medium magnification cases, the results from both methods are indistinguishable as they give the same underestimation of the real velocities (approximately 33%, based on in vitro reference measurements. These results suggest that flow characteristics reported in literature cannot be compared without a careful evaluation of the imaging characteristics. A method to predict the expected flow averaging behavior for a particular facility is presented.

  8. An evaluation of blood smears made by a new method using a spinner and diluted blood.

    Science.gov (United States)

    Nourbakhsh, M; Atwood, J G; Raccio, J; Seligson, D

    1978-12-01

    Blood smears were prepared with the use of a spinner, which rotated with a fixed velocity for a fixed time. All blood samples used for spun smears were diluted with a fixed ratio of buffered isotonic saline solution. Distribution of cells in these smears was found to be random. The average number of cells per unit area was substantially uniform from place to place on the same slide and on multiple slides made with the smae sample. The distribution of leukocytes by type was also iniform. For different blood samples, the average number of cells per unit area in the smears correlated well with the measured cell concentrations per unit volume in the samples for leukocytes, erythrocytes and platelets. Leukocyte differential counts on replicate spun smears using the same bloods also agreed to within the sampling error. They similarly agreed with differential counts on pulled smears made from undiluted samples of the same bloods. With few exceptions, erythrocytic morphology on the spun smears was comparable to that on the good areas of pulled smears made with undiluted samples of the same bloods. Nearly all the spun smears were suitable for both viual and fully automated hematologic examination for leukocytes, erythrocytes, and platelets. This was true over nearly the whole area of each spun slide. In these ways this spinner method makes smears whose consistently high quality is little affected by either the properties of the blood sample or the skill of maker.

  9. [Double-blind evaluation of slow-release nicardipine using different methods of blood pressure measurement. Predictive value of the acute response to intravenous nicardipine].

    Science.gov (United States)

    Bellet, B; Pagny, J Y; Chatellier, G; Frère, R; Ménard, D; Corvol, P; Ménard, J

    1987-06-01

    Forty hypertensive patients (diastolic greater than 95 mmHg) were included after 15 days of a single blind placebo period in a randomized placebo controlled double-blind study to assess the antihypertensive effect of a new galenic form of nicardipine (N) administered 50 mg b.i.d. for 3 weeks. They comprised 27 men and 13 women aged from 27 to 72 years (mean: 53 +/- 10). Blood pressure (BP) was measured in hospital before morning drug intake by an automatic recorder (Sentron) in supine position for 30 minutes (min) and by a mercury sphygmomanometer. Ambulatory BP was assessed by a portable patient activated recorder (Remler 2000). Mercury sphygmomanometer supine BP under N fell from 160 +/- 21/104 +/- 6 mmHg to 151 +/- 14/98 +/- 8 mmHg (n = 20; p less than 0.01/p less than 0.01) whereas BP under placebo (P) was respectively 158 +/- 14/103 +/- 6 mmHg and 156 +/- 20/102 +/- 9 mmHg (NS). Sentron BP under N fell from 158 +/- 17/96 +/- 8 mmHg to 148 +/- 13/90 +/- 7 mmHg (p less than 0.001/p less than 0.01) with no BP change under P (152 +/- 12/93 +/- 7 mmHg to 151 +/- 14/93 +/- 8 mmHg NS). BP recorder every 30 min for 12 hours revealed a decrease under N (160 +/- 18/105 +/- 10 mmHg to 142 +/- 16/94 +/- 10 mmHg; p less than 0.001/p less than 0.001) with a placebo effect in the control group on the diastolic BP (160 +/- 15/103 +/- 7 mmHg to 156 +/- 16/100 +/- 8 mmHg/NS/p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3116985

  10. 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...

  11. 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.

  12. 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

  13. 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.

  14. Pressure Gradient Estimation Based on Ultrasonic Blood Flow Measurement

    Science.gov (United States)

    Nitta, Naotaka; Homma, Kazuhiro; Shiina, Tsuyoshi

    2006-05-01

    Mechanical load to the blood vessel wall, such as shear stress and pressure, which occurs in blood flow dynamics, contribute greatly to plaque rupture in arteriosclerosis and to biochemical activation of endothelial cells. Therefore, noninvasive estimations of these mechanical loads are able to provide useful information for the prevention of vascular diseases. Although the pressure is the dominant component of mechanical load, for practical purposes, the pressure gradient is also often important. So far, we have investigated the estimation of the kinematic viscosity coefficient using a combination of the Navier-Stokes equations and ultrasonic velocity measurement. In this paper, a method for pressure gradient estimation using the estimated kinematic viscosity coefficient is proposed. The validity of the proposed method was investigated on the basis of the analysis with the data obtained by computer simulation and a flow phantom experiment. These results revealed that the proposed method can provide a valid estimation of the pressure gradient.

  15. 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

  16. Method for measurement of the blood-brain barrier permeability in the perfused mouse brain: application to amyloid-beta peptide in wild type and Alzheimer's Tg2576 mice.

    Science.gov (United States)

    LaRue, Barbra; Hogg, Elizabeth; Sagare, Abhay; Jovanovic, Suzana; Maness, Lawrence; Maurer, Calvin; Deane, Rashid; Zlokovic, Berislav V

    2004-09-30

    The role of transport exchanges of neuroactive solutes across the blood-brain barrier (BBB) is increasingly recognized. To take full advantage of genetically altered mouse models of neurodegenerative disorders for BBB transport studies, we adapted a brain perfusion technique to the mouse. During a carotid brain perfusion with a medium containing sheep red blood cells and mock plasma, the physiological parameters in the arterial inflow, regional cerebral blood flow (14C-iodoantipyrine autoradiography), ultrastructural integrity of the tissue, barrier to lanthanum, brain water content, energy metabolites and lactate levels remain unchanged. Amyloid-beta peptides (Abeta) were iodinated by lactoperoxidase method. Non-oxidized mono-iodinated Abeta monomers were separated by HPLC (as confirmed by MALDI-TOF spectrometry) and used in transport measurements. Transport of intact 125I-Abeta40 across the BBB was time- and concentration-dependent in contrast to negligible 14C-inulin uptake. In 5-6 months old Alzheimer's Tg2576 mice, Abeta40 BBB transport was increased by >eight-fold compared to age-matched littermate controls, and was mediated via the receptor for advanced glycation endproducts. We conclude the present arterial brain perfusion method provides strictly controlled environment in cerebral microcirculation suitable for examining transport of rapidly and slowly penetrating molecules across the BBB in normal and transgenic mice.

  17. 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...

  18. 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...

  19. 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 ...

  20. 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

  1. 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.

  2. 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 a...

  3. 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.

  4. 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

  5. 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.

  6. MEASUREMENT OF REGIONAL BONE BLOOD FLOW IN THE CANINE MANDIBULAR RAMUS USING RADIOLABELLED TOAD RED BLOOD CELLS

    Institute of Scientific and Technical Information of China (English)

    毛驰; 王翰章

    1994-01-01

    Toad red blood cells were used to measure regional bone blood flow in the canine mandibular ramus.The blood cells were labelled with sodium pertechnetate and fixed in 10% formalin;they were 22×15 μm in size and had a specific gravity close to that of dog red blood cells.These cells had no discernible effect on systemic hemody-namics after injection,did not agglutinate,were well mixed and evenly distributed throughout the body,and were completely extracted in one circulation through the mandible.The mandibular ramus was divided into six regions,and the blood flow rates in each were found to be similar to those reported in previous studies with radiolabelled carbonized,microspheres.Furthermore,the blood flow distribution pattern of the mandibular ramus determined in this study was identical to that of our previous study using the bone-seeking radionuclide method.We suggest that radiolabelled toad red blood cells are an ideal marker for measuring regional blood flow in the canine mandible.

  7. 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)

  8. Hemoglobin measured by Hemocue and a reference method in venous and capillary blood: a validation study Hemoglobina medida por Hemocue y por un método de referencia en sangre venosa y capilar: estudio de validación

    Directory of Open Access Journals (Sweden)

    Lynnette Neufeld

    2002-06-01

    Full Text Available Objective. To assess the comparability of hemoglobin concentration (Hb in venous and capillary blood measured by Hemocue and an automated spectrophotometer (Celldyn and to document the influence of type of blood (capillary or venous and analysis method on anemia prevalence estimates. Material and Methods. Between February and May 2000, capillary and venous samples were collected from 72 adults and children at Hospital del Niño Morelense (Morelos State Children's Hospital in Cuernavaca, Morelos, Mexico, and assessed for Hb using the Hemocue and Celldyn methods. Estimated Hb levels were compared using the concordance correlation coefficient and Student's t test for paired data. The sensitivity and specificity for anemia diagnosis were estimated and compared between type of blood and method of assessment. Results. Capillary blood had higher Hb (+0.5g/dl than venous blood in adults and children, as did samples assessed by Celldyn compared to Hemocue (+0.3g/dl. Specificity to detect anemia was adequate (>0.90 but sensitivity was low for capillary blood assessed by Hemocue (Objetivo. Evaluar la comparabilidad de la concentración de hemoglobina (Hb en sangre venosa y capilar medida por Hemocue y por espectrofotómetro automatizado (Celldyn, así como documentar la influencia del tipo de sangre (capilar o venosa y del método de análisis sobre la prevalencia de anemia. Material y métodos. De febrero a mayo de 2000, se recolectaron muestras de sangre capilar y venosa en 72 adultos y niños en el Hospital del Niño Morelense, Cuernavaca, Morelos, México. Se determinaron los niveles de Hb con los métodos Hemocue y Celldyn. Las cifras de Hb estimadas se compararon con el coeficiente de concordancia y la prueba pareada de t de Student. También se comparó la sensibilidad y especificidad para el diagnóstico de anemia, utilizando sangre de los dos tipos y métodos de análisis. Resultados. La Hb fue mayor en sangre capilar comparada con sangre venosa

  9. Methods of radon measurement

    Directory of Open Access Journals (Sweden)

    Forkapić S.

    2006-01-01

    Full Text Available Several important international scientific organizations have designated radon as a carcinogenic and serious health problem. As a chemically inert gas, it is easily released from soil, building materials, and water, to emanate to the atmosphere. Since 1992, Laboratory for Nuclear Physics of the Department of Physics, Faculty of Sciences in Novi Sad has been involved in measurements of radon concentration in air, using several different techniques. Last year, systematic radon measurements in drinking waters began, too. The work presented here gives a survey and discussion of the results of the both series of measurements.

  10. Blood pressure measurement in hemodialysis: The importance of the measurement technique.

    Science.gov (United States)

    Kubrusly, M; de Oliveira, Claudia Maria Costa; Silva, R P; Pinheiro, M A; Rocha, M B C; Magalhães, R M

    2016-03-01

    Systemic arterial hypertension contributes to the high cardiovascular morbidity in hemodialysis (HD) patients, but the accuracy of blood pressure (BP) measurement in this population has not been well studied. To evaluate the agreement between BP measurement using the routine measurement technique (usual method) and the technique recommended by the VII Joint (standard method). This cross-sectional study enrolled 124 patients in a single center who had undergone dialysis for more than three months and were 18 years of age or older. The BP was verified at the start of dialysis by the nursing team (usual method) and by the researchers (standard method). The agreement between the systolic and diastolic BP (SBP and DBP) measurements was tested by the Bland-Altman analysis. A difference in BP measurement higher than ±5 mm Hg was considered clinically significant. The studied group had a mean age of 53.2 years. The average difference between routine and standard BP measurement was -6 mm Hg for SBP (limits of agreement: -40.1-28 mm Hg; P measured by both methods was observed in 69.4% of the patients for SBP and in 61.3% for DBP. The disagreement between the results of different BP measurement methods in HD patients was significant and the BP was underestimated using the usual BP method. BP measurement standardization should be encouraged to avoid errors in diagnosis and therapy.

  11. 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...

  12. Dynamic noise correction for IVUS quantitative volume blood flow: methods and numerical validation.

    NARCIS (Netherlands)

    Lupotti, F.A.; Korte, C.L. de; Mastik, F.; Steen, A.F.W. van der

    2002-01-01

    In recent years, a new method to measure transverse blood flow based on the decorrelation of the radio-frequency (RF) signals, has been developed. Transverse blood flow estimation may be influenced by noise. In this paper, we investigated a new correlation-based method for noise correction. The deco

  13. 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

    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 o...

  14. 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.

  15. 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;

    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...

  16. 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

  17. 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......

  18. 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

  19. 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.

  20. 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.)

  1. Spectral feature characterization methods for blood stain detection in crime scene backgrounds

    Science.gov (United States)

    Yang, Jie; Mathew, Jobin J.; Dube, Roger R.; Messinger, David W.

    2016-05-01

    Blood stains are one of the most important types of evidence for forensic investigation. They contain valuable DNA information, and the pattern of the stains can suggest specifics about the nature of the violence that transpired at the scene. Blood spectral signatures containing unique reflectance or absorption features are important both for forensic on-site investigation and laboratory testing. They can be used for target detection and identification applied to crime scene hyperspectral imagery, and also be utilized to analyze the spectral variation of blood on various backgrounds. Non-blood stains often mislead the detection and can generate false alarms at a real crime scene, especially for dark and red backgrounds. This paper measured the reflectance of liquid blood and 9 kinds of non-blood samples in the range of 350 nm - 2500 nm in various crime scene backgrounds, such as pure samples contained in petri dish with various thicknesses, mixed samples with different colors and materials of fabrics, and mixed samples with wood, all of which are examined to provide sub-visual evidence for detecting and recognizing blood from non-blood samples in a realistic crime scene. The spectral difference between blood and non-blood samples are examined and spectral features such as "peaks" and "depths" of reflectance are selected. Two blood stain detection methods are proposed in this paper. The first method uses index to denote the ratio of "depth" minus "peak" over"depth" add"peak" within a wavelength range of the reflectance spectrum. The second method uses relative band depth of the selected wavelength ranges of the reflectance spectrum. Results show that the index method is able to discriminate blood from non-blood samples in most tested crime scene backgrounds, but is not able to detect it from black felt. Whereas the relative band depth method is able to discriminate blood from non-blood samples on all of the tested background material types and colors.

  2. Prediction Methods for Blood Glucose Concentration

    DEFF Research Database (Denmark)

    measurements which are also subject to measurement errors. Inaccurate measurements will directly affect the performance of the corresponding predictions. The chapter “CGM — How Good Is Good Enough?” by Michael Schoemaker and Christopher G. Parkin also tackles the problem of continuous glucose monitor...

  3. 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...

  4. 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.

  5. 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

  6. Determining tumor blood flow parameters from dynamic image measurements

    Science.gov (United States)

    Libertini, Jessica M.

    2008-11-01

    Many recent cancer treatments focus on preventing angiogenesis, the process by which a tumor promotes the growth of large and efficient capillary beds for the increased nourishment required to support the tumor's rapid growth[l]. To measure the efficacy of these treatments in a timely fashion, there is an interest in using data from dynamic sequences of contrast-enhanced medical imaging, such as MRI and CT, to measure blood flow parameters such as perfusion, permeability-surface-area product, and the relative volumes of the plasma and extracellular-extravascular space. Starting with a two compartment model presented by the radiology community[2], this work challenges the application of a simplification to this problem, which was originally developed to model capillary reuptake[3]. While the primary result of this work is the demonstration of the inaccuracy of this simplification, the remainder of the paper is dedicated to presenting alternative methods for calculating the perfusion and plasma volume coefficients. These methods are applied to model data sets based on real patient data, and preliminary results are presented.

  7. Determining tumor blood flow parameters from dynamic image measurements

    Energy Technology Data Exchange (ETDEWEB)

    Libertini, Jessica M [Division of Applied Mathematics, Brown University, Providence, Rhode Island 02906 (United States)], E-mail: Jessica_Libertini@brown.edu

    2008-11-01

    Many recent cancer treatments focus on preventing angiogenesis, the process by which a tumor promotes the growth of large and efficient capillary beds for the increased nourishment required to support the tumor's rapid growth. To measure the efficacy of these treatments in a timely fashion, there is an interest in using data from dynamic sequences of contrast-enhanced medical imaging, such as MRI and CT, to measure blood flow parameters such as perfusion, permeability-surface-area product, and the relative volumes of the plasma and extracellular-extravascular space. Starting with a two compartment model presented by the radiology community, this work challenges the application of a simplification to this problem, which was originally developed to model capillary reuptake. While the primary result of this work is the demonstration of the inaccuracy of this simplification, the remainder of the paper is dedicated to presenting alternative methods for calculating the perfusion and plasma volume coefficients. These methods are applied to model data sets based on real patient data, and preliminary results are presented.

  8. 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

  9. Automated methods of corrosion measurement

    DEFF Research Database (Denmark)

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

    1997-01-01

    Measurements of corrosion rates and other parameters connected with corrosion processes are important, first as indicators of the corrosion resistance of metallic materials and second because such measurements are based on general and fundamental physical, chemical, and electrochemical relations....... Hence improvements and innovations in methods applied in corrosion research are likeliy to benefit basic disciplines as well. A method for corrosion measurements can only provide reliable data if the beckground of the method is fully understood. Failure of a method to give correct data indicates a need...... 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. Automation...

  10. 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

  11. 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.......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 use...

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Evaluating measurement error in readings of blood pressure for adolescents and young adults.

    Science.gov (United States)

    Bauldry, Shawn; Bollen, Kenneth A; Adair, Linda S

    2015-04-01

    Readings of blood pressure are known to be subject to measurement error, but the optimal method for combining multiple readings is unknown. This study assesses different sources of measurement error in blood pressure readings and assesses methods for combining multiple readings using data from a sample of adolescents/young adults who were part of a longitudinal epidemiological study based in Cebu, Philippines. Three sets of blood pressure readings were collected at 2-year intervals for 2127 adolescents and young adults as part of the Cebu National Longitudinal Health and Nutrition Study. Multi-trait, multi-method (MTMM) structural equation models in different groups were used to decompose measurement error in the blood pressure readings into systematic and random components and to examine patterns in the measurement across males and females and over time. The results reveal differences in the measurement properties of blood pressure readings by sex and over time that suggest the combination of multiple readings should be handled separately for these groups at different time points. The results indicate that an average (mean) of the blood pressure readings has high validity relative to a more complicated factor-score-based linear combination of the readings. PMID:25548966

  18. Measuring the antioxidant capacity of blood plasma using potentiometry.

    Science.gov (United States)

    Tessutti, L S; Macedo, D V; Kubota, L T; Alves, A A

    2013-10-15

    The use of potentiometry to measure plasma antioxidant capacity to contribute to oxidative stress evaluation is presented. In this assay, plasma (n=60) diluted (0.3 to 1 ml) in phosphate buffer, pH 7.4, NaCl 9%, was submitted to potentiometry. A platinum wire was the working electrode and saturated calomel the reference. The results are presented as the difference between sample and buffer potential (ΔE). ΔE presented a good inverse correlation with added increasing concentrations of ascorbate (2.5-75 μmol/L; R=-0.99), urate (9.0-150 μmol/L; R=-0.99), and bilirubin (0.78-13 μmol/L; R=-0.99). Increase in the antioxidant capacity decreased ΔE. Depletion of the antioxidant capacity by tert-butylhydroperoxide (6.5-50 μmol/L) presented a direct correlation (0.97) with ΔE. Furthermore, ΔE presented an inverse correlation (R=-0.99) with increased antioxidant capacity of plasma (FRAP) induced by the addition of ascorbate (2.5-75 μmol/L). The response of the potentiometric method proved be adequate for measuring the plasma antioxidant depletion induced by acute exhaustive exercise in rats (control, n=15; exercised, n=15). This exercise decreased the concentration of urate (ppotentiometry for evaluating the antioxidant capacity of blood plasma samples.

  19. Blood cell manufacture: current methods and future challenges.

    Science.gov (United States)

    Timmins, Nicholas E; Nielsen, Lars K

    2009-07-01

    Blood transfusion depends on availability of donor material, and concerns over supply and safety have spurred development of methods to manufacture blood from stem cells. Current methods could theoretically yield therapeutic doses of red blood cells (RBCs) and platelets. However, due to the very large number of cells required to have any impact on supply (currently 10(19) RBC/year in the US), realization of routine manufacture faces significant challenges. Current yields are orders of magnitude too low for production of meaningful quantities, and the physical scale of the problem is a challenge in itself. We discuss these challenges in relation to current methods and how it might be possible to realize limited 'blood pharming' of neutrophils in the near future. PMID:19500866

  20. Blood cell manufacture: current methods and future challenges.

    Science.gov (United States)

    Timmins, Nicholas E; Nielsen, Lars K

    2009-07-01

    Blood transfusion depends on availability of donor material, and concerns over supply and safety have spurred development of methods to manufacture blood from stem cells. Current methods could theoretically yield therapeutic doses of red blood cells (RBCs) and platelets. However, due to the very large number of cells required to have any impact on supply (currently 10(19) RBC/year in the US), realization of routine manufacture faces significant challenges. Current yields are orders of magnitude too low for production of meaningful quantities, and the physical scale of the problem is a challenge in itself. We discuss these challenges in relation to current methods and how it might be possible to realize limited 'blood pharming' of neutrophils in the near future.

  1. A spectral and morphologic method for white blood cell classification

    Science.gov (United States)

    Wang, Qian; Chang, Li; Zhou, Mei; Li, Qingli; Liu, Hongying; Guo, Fangmin

    2016-10-01

    The identification of white blood cells is important as it provides an assay for diagnosis of various diseases. To overcome the complexity and inaccuracy of traditional methods based on light microscopy, we proposed a spectral and morphologic method based on hyperspectral blood images. We applied mathematical morphology-based methods to extract spatial information and supervised method is employed for spectral analysis. Experimental results show that white blood cells could be segmented and classified into five types with an overall accuracy of more than 90%. Moreover, the experiments including spectral features reached higher accuracy than the spatial-only cases, with a maximum improvement of nearly 20%. By combing both spatial and spectral features, the proposed method provides higher classification accuracy than traditional methods.

  2. 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...

  3. 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...

  4. A method for estimation of plasma albumin concentration from the buffering properties of whole blood

    DEFF Research Database (Denmark)

    Rees, Stephen Edward; Diemer, Tue; Kristensen, Søren Risom

    2012-01-01

    measurements of acid-base and oxygenation status. This article presents and evaluates a new method for doing so. MATERIALS AND METHODS: The mathematical method for estimating plasma albumin concentration is described. To evaluate the method at numerous albumin concentrations, blood from 19 healthy subjects......PURPOSE: Hypoalbuminemia is strongly associated with poor clinical outcome. Albumin is usually measured at the central laboratory rather than point of care, but in principle, information exists in the buffering properties of whole blood to estimate plasma albumin concentration from point of care...

  5. [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

  6. 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

  7. Direct detection of red blood cell fragments: a new flow cytometric method to evaluate hemolysis in blood pumps.

    Science.gov (United States)

    Linneweber, J; Chow, T W; Takano, T; Maeda, T; Nonaka, K; Schulte-Eistrup, S; Kawahito, S; Elert, O; Moake, J L; Nosé, Y

    2001-01-01

    Pump induced hemolysis is presently evaluated by measuring plasma free hemoglobin (fHb). However, this method has disadvantages because quantification of fHb depends on hematocrit (HCT) and hemoglobin (Hb) levels. The aim of this work was to devise a hemoglobin independent method, capable of quantifying cell trauma directly by measuring the number of red blood cell (RBC) fragments. Whole blood flow cytometry was used to quantify circulating RBC fragments derived from a roller pump (Sarns, Inc. Model 2 M 6,002) and a centrifugal pump (Gyro C1E3, Kyocera Corp.). The pumps were tested in a mock circuit for 2 hr (5 L/min flow against 100 mm Hg pressure head). Red blood cell fragments were quantified by a phycoerythrin (PE) labeled glycophorin A antibody specific for erythrocytes. Red blood cell fragments were smaller than the intact RBC population and overlapped in size with the platelet population (based on forward- and side-light scattering measurements). For the roller pump, the values for RBC fragments increased from 1,090 +/- 260/microl at 0 min to 14,880 +/- 5,900/microl after 120 min. In contrast, using the centrifugal pump, there was little increase in RBC fragments (from 730 +/- 270/microl at 0 min to 1,400 +/- 840/microl after 120 min). Flow cytometry can be used for the rapid, sensitive, hemoglobin independent evaluation of pump induced RBC trauma.

  8. 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...

  9. 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)

  10. 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.

  11. Spectrophotometric determination of total proteins in blood plasma: a comparative study among dye-binding methods

    OpenAIRE

    Dimas Augusto Morozin Zaia; Fábio Rangel Marques; Cássia Thaïs Bussamra Vieira Zaia

    2005-01-01

    A comparative study between the biuret method (standard method for total proteins) and spectrophotometric methods using dyes (Bradford, 3',3",5',5"-tetrabromophenolphthalein ethyl ester-TBPEE, and erythrosin-B) was carried out for the determination of total proteins in blood plasma from rats. Bradford method showed the highest sensitivity for proteins and biuret method showed the lowest. For all the methods, the absorbance for different proteins (BSA, casein, and egg albumin) was measured and...

  12. 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

  13. [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

  14. Ultrasonic Measurement of Fluid Viscosity for Blood Characterization

    Science.gov (United States)

    Nitta, Naotaka; Homma, Kazuhiro

    2005-06-01

    Although plaque rupture in arteriosclerosis is affected by not only its strength but also by hemodynamic factors, such as blood pressure and shear stress, in particular, the viscous coefficient which directly controls the magnitude of shear stress might be a risk factor in plaque rupture. Therefore, if the viscous coefficient can be assessed noninvasively, it can be a useful index for prediction of a plaque rupture and assessment of various diseases. In this work, an ultrasonic methodology to estimate the viscous coefficient was investigated by numerical simulation and flow-phantom experiment as the fundamental investigation for noninvasively assessing the viscous characteristics of blood. These results show that the proposed method is useful for estimating the kinematic viscosity coefficient in the viscous evaluation of blood.

  15. Laser optical method of visualizing cutaneous blood vessels and its applications in biometry and photomedicine

    Science.gov (United States)

    Asimov, M. M.; Asimov, R. M.; Rubinov, A. N.

    2011-05-01

    We propose and examine a new approach to visualizing a local network of cutaneous blood vessels using laser optical methods for applications in biometry and photomedicine. Various optical schemes of the formation of biometrical information on the architecture of blood vessels of skin tissue are analyzed. We developed an optical model of the interaction of the laser radiation with the biological tissue and a mathematical algorithm of processing of measurement results. We show that, in medicine, the visualization of blood vessels makes it possible to calculate and determine regions of disturbance of blood microcirculation and to control tissue hypoxia, as well as to maintain the local concentration of oxygen at a level necessary for the normal cellular metabolism. We propose noninvasive optical methods for modern photomedicine and biometry for diagnostics and elimination of tissue hypoxia and for personality identification and verification via the pattern of cutaneous blood vessels.

  16. 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。

  17. 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...

  18. 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

  19. 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)

  20. 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

  1. 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)

  2. Association between routine and standardized blood pressure measurements and left ventricular hypertrophy among patients on hemodialysis

    Directory of Open Access Journals (Sweden)

    Walsh Michael

    2010-06-01

    Full Text Available Abstract Background Left ventricular (LV hypertrophy is common among patients on hemodialysis. While a relationship between blood pressure (BP and LV hypertrophy has been established, it is unclear which BP measurement method is the strongest correlate of LV hypertrophy. We sought to determine agreement between various blood pressure measurement methods, as well as identify which method was the strongest correlate of LV hypertrophy among patients on hemodialysis. Methods This was a post-hoc analysis of data from a randomized controlled trial. We evaluated the agreement between seven BP measurement methods: standardized measurement at baseline; single pre- and post-dialysis, as well as mean intra-dialytic measurement at baseline; and cumulative pre-, intra- and post-dialysis readings (an average of 12 monthly readings based on a single day per month. Agreement was assessed using Lin's concordance correlation coefficient (CCC and the Bland Altman method. Association between BP measurement method and LV hypertrophy on baseline cardiac MRI was determined using receiver operating characteristic curves and area under the curve (AUC. Results Agreement between BP measurement methods in the 39 patients on hemodialysis varied considerably, from a CCC of 0.35 to 0.94, with overlapping 95% confidence intervals. Pre-dialysis measurements were the weakest predictors of LV hypertrophy while standardized, post- and inter-dialytic measurements had similar and strong (AUC 0.79 to 0.80 predictive power for LV hypertrophy. Conclusions A single standardized BP has strong predictive power for LV hypertrophy and performs just as well as more resource intensive cumulative measurements, whereas pre-dialysis blood pressure measurements have the weakest predictive power for LV hypertrophy. Current guidelines, which recommend using pre-dialysis measurements, should be revisited to confirm these results.

  3. 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.

  4. 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...

  5. 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.

  6. 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...

  7. 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.

  8. 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

    a close correlation to the blood flow values determined with microspheres. Y = 0.98. X + 0.15 (r = 0.96, P less than 0.001). The Xe clearance method has the advantages compared to the microsphere technique that it permits continuous monitoring of the blood flow and does not require the sacrifice......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...

  9. 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

  10. Four-Parameter white blood cell differential counting based on light scattering measurements

    NARCIS (Netherlands)

    Terstappen, L.W.M.M.; Grooth, de B.G.; Visscher, K.; Kouterik, F.A.; Greve, J.

    1988-01-01

    Measurement of the depolarized orthogonal light scattering in flow cytometry enables one to discriminate human eosinephilic granulocytes from neutrophilic granulocytes. We use this method to perform a four-parameter differential white blood cell analysis. A simple flow cytometer was built equipped

  11. 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

  12. 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

  13. 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

    technique arterial spin labelling (ASL) presently provides measurement only of cerebral blood flow (CBF), which has not been widely used in human brain tumor studies. Purpose: To assess if measurement of blood flow is comparable with measurement of blood volume in human biopsy-proven gliomas obtained by DSC......, and 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......-MRI using two different regions for normalization and two different measurement approaches. Material and Methods: Retrospective study of 61 patients with different types of gliomas examined with DSC perfusion MRI. Regions of interest (ROIs) were placed in tumor portions with maximum perfusion on rCBF and r...

  14. 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.

  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. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. Quantitative photoacoustic blood oxygenation measurement of whole porcine blood samples using a multi-wavelength semiconductor laser system

    Science.gov (United States)

    Friedrich, Claus-Stefan; Mienkina, Martin P.; Brenner, Carsten; Gerhardt, Nils C.; Jörger, Manfred; Strauß, Andreas; Beckmann, Martin F.; Schmitz, Georg; Hofmann, Martin R.

    2011-07-01

    We present a photoacoustic measurement system based on semiconductor lasers for blood oxygenation measurements. It permits to use four different optical wavelengths (650nm, 808nm, 850nm, 905nm) to generate photoacoustic signals. As the optical extinction coefficient of oxygenated hemoglobin and deoxygenated hemoglobin is different at specific wavelengths, a blood oxygenation measurement by a multi-wavelength photoacoustic laser system is feasible. Especially at 650nm, the clear difference between the extinction coefficients of the two hemoglobin derivates permits to determine the blood oxygenation in combination with other near infrared wavelengths. A linear model based on tabulated values of extinction coefficients for fully oxygenated and fully deoxygenated hemoglobin is presented. We used heparin stabilized whole porcine blood samples to model the optical behavior of human blood, as the optical absorption behavior of porcine hemoglobin does not differ significantly from human hemoglobin. To determine the real oxygen saturation values of the blood samples, we measured the partial oxygen pressure with an IRMA Trupoint Blood Analysis System. The oxygen saturation values were calculated from a dissociation curve for porcine blood. The results of the photoacoustic measurement are in qualitatively good agreement with the predicted linear model. Further, we analyze the abilities and the limitations of quantitative oxygenation measurements.

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

    Energy Technology Data Exchange (ETDEWEB)

    Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem]. E-mail: ar.leao@uol.com.br; Colleoni, Ramiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Gastroenterologia

    2008-09-15

    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)

  5. Application of Servqual evaluation method in measuring service quality of blood collection%Servqual评价法在门诊采血服务质量评价中的调查

    Institute of Scientific and Technical Information of China (English)

    郭惠子; 纪代红

    2015-01-01

    Objective Investigating the present situation of nursing service in tertiary general hospital blood specimen col-lection to find out the key factors affecting the quality of service. Methods The Servqual scale was used among 300 patients with blood collecting. Results The perceived service quality score of every hospital was negative,the difference of Tangible、Reliability、Responsiveness、Assurance、Empathy of different hospitals was statistically significant (P<0.05).And the effect of gender and payment mode of medical expenses for perceived service quality were statistically significant(P<0.05). Conclu-sions The service quality of blood specimen collection remains to be further improved,Servqual scale can objectively and ef-fectively analyze the key problem of nursing service quality.%目的:应用Servqual评价法调查三级甲等综合医院门诊血液标本采集服务质量现状,探讨影响感知服务质量的因素。方法应用基于Servqual评价法的服务质量测评量表对300例门诊血液标本采集患者进行调查。结果各三级甲等医院的感知服务质量均为负值,不同医院感知服务质量在有形性、可靠性、响应性、保证性、移情性五个维度上的差异有统计学意义(P<0.05)。比较性别和医疗费用支付情况对感知服务质量的影响,差异有统计学意义(P<0.05)。结论门诊采血服务质量有待进一步提高,Servqual量表能够客观、有效地分析出影响护理服务质量的关键问题,对持续性改进服务质量具有重要意义。

  6. 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.

  7. Estimation of intersubject variability of cerebral blood flow measurements using MRI and positron emission tomography

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Larsson, Henrik B W; Hansen, Adam E;

    2012-01-01

    PURPOSE: To investigate the within and between subject variability of quantitative cerebral blood flow (CBF) measurements in normal subjects using various MRI techniques and positron emission tomography (PET). MATERIALS AND METHODS: Repeated CBF measurements were performed in 17 healthy, young...... subjects using three different MRI techniques: arterial spin labeling (ASL), dynamic contrast enhanced T1 weighted perfusion MRI (DCE) and phase contrast mapping (PCM). All MRI measurements were performed within the same session. In 10 of the subjects repeated CBF measurements by (15) O labeled water PET...

  8. 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

  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. 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

  11. [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

  12. 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.

  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. 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.

  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. 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

  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. 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....

  20. Measuring blood delivery to solitary pulmonary nodules using perfusion magnetic resonance imaging

    Science.gov (United States)

    Zheng, Wei; Wang, Zhifeng; Shen, Li; Gao, Ling; Ford, James C.; Makedon, Fillia S.; Pearlman, Justin D.

    2006-03-01

    With perfusion magnetic resonance imaging (pMRI), perfusion describes the amount of blood passing through a block of tissue in a certain period of time. In pMRI, the tissue having more blood passing through will show higher intensity value as more contrast-labeled blood arrives. Perfusion reflects the delivery of essential nutrients to a block of tissue, and is an important parameter for the tissue status. Considering solitary pulmonary nodules (SPN), perfusion differences between malignant and benign nodules have been studied by different techniques. Much effort has been put into its characterization. In this paper, we proposed and implemented extraction of the SPN time intensity profile to measure blood delivery to solitary pulmonary nodules, describing their perfusion effects. In this method, a SPN time intensity profile is created based on intensity values of the solitary pulmonary nodule in lung pMRI images over time. This method has two steps: nodule tracking and profile clustering. Nodule tracking aligns the solitary pulmonary nodule in pMRI images taken at different time points, dealing with nodule movement resulted from breathing and body movement. Profile clustering implements segmentation of the nodule region and extraction of the time intensity profile of a solitary pulmonary nodule. SPN time intensity profiles reflect patterns of blood delivery to solitary pulmonary nodules, giving us a description of perfusion effect and indirect evidence of tumor angiogenesis. Analysis on SPN time intensity profiles will help the diagnosis of malignant nodules for early lung cancer detection.

  1. 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.

  2. 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.

  3. 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 ...

  4. The Choroidal Eye Oximeter - An instrument for measuring oxygen saturation of choroidal blood in vivo

    Science.gov (United States)

    Laing, R. A.; Danisch, L. A.; Young, L. R.

    1975-01-01

    The Choroidal Eye Oximeter is an electro-optical instrument that noninvasively measures the oxygen saturation of choroidal blood in the back of the human eye by a spectrophotometric method. Since choroidal blood is characteristic of blood which is supplied to the brain, the Choroidal Eye Oximeter can be used to monitor the amount of oxygen which is supplied to the brain under varying external conditions. The instrument consists of two basic systems: the optical system and the electronic system. The optical system produces a suitable bi-chromatic beam of light, reflects this beam from the fundus of the subject's eye, and onto a low-noise photodetector. The electronic system amplifies the weak composite signal from the photodetector, computes the average oxygen saturation from the area of the fundus that was sampled, and displays the value of the computed oxygen saturation on a panel meter.

  5. 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

  6. Comparison of Different Blood Collection, Sample Matrix, and Immunoassay Methods in a Prenatal Screening Setting

    Directory of Open Access Journals (Sweden)

    Jeroen L. A. Pennings

    2014-01-01

    Full Text Available We compared how measurements of pregnancy-associated plasma protein A (PAPP-A and the free beta subunit of human chorionic gonadotropin (fβ-hCG in maternal blood are influenced by different methods for blood collection, sample matrix, and immunoassay platform. Serum and dried blood spots (DBS were obtained by venipuncture and by finger prick of 19 pregnant women. PAPP-A and fβ-hCG from serum and from DBS were measured by conventional indirect immunoassay on an AutoDELFIA platform and by antibody microarray. We compared methods based on the recoveries for both markers as well as marker levels correlations across samples. All method comparisons showed high correlations for both marker concentrations. Recovery levels of PAPP-A from DBS were 30% lower, while those of fβ-hCG from DBS were 50% higher compared to conventional venipuncture serum. The recoveries were not affected by blood collection or immunoassay method. The high correlation coefficients for both markers indicate that DBS from finger prick can be used reliably in a prenatal screening setting, as a less costly and minimally invasive alternative for venipuncture serum, with great logistical advantages. Additionally, the use of antibody arrays will allow for extending the number of first trimester screening markers on maternal and fetal health.

  7. Tomographic cerebral blood flow measurement during carotid surgery

    DEFF Research Database (Denmark)

    Rathenborg, Lisbet Knudsen; Vorstrup, Sidsel; Olsen, K S;

    1994-01-01

    surgery and performing single photon emission computer tomography (SPECT) scanning shortly after the operation thereby pictures rCBF at the time of injection. DESIGN: Ongoing prospective study. SETTINGS: Departments of Vascular Surgery, Neurology and Anaesthesiology, University Hospital, Rigshospitalet......, Copenhagen, Denmark. MATERIAL: 15 patients who during a period of 4 months underwent carotid endarterectomy. CHIEF OUTCOME MEASURES: Prior to surgery rCBF was determined using 133Xe and SPECT. Intraoperatively stump pressure was measured and a bolus of TcHMPAO was injected for later SPECT measurement. MAIN...... carotid surgery. This method may serve as a reference tool in future research on intraoperative cerebral haemodynamics....

  8. 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...

  9. 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.)

  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. Two-photon microscopy with double-circle trajectories for in vivo cerebral blood flow measurements

    Science.gov (United States)

    Landolt, Andrin; Obrist, Dominik; Wyss, Matthias; Barrett, Matthew; Langer, Dominik; Jolivet, Renaud; Soltysinski, Tomasz; Roesgen, Thomas; Weber, Bruno

    2013-05-01

    Scanning microscopes normally use trajectories which produce full-frame images of an object at a low frame rate. Time-resolved measurements are possible if scans along a single line are repeated at a high rate. In conjunction with fluorescence labeling techniques, in vivo recording of blood flow in single capillaries is possible. The present work investigates scanning with double-circle trajectories to measure blood flow simultaneously in several vessels of a capillary network. With the trajectory centered near a bifurcation, a double circle crosses each vessel twice, creating a sensing gate for passing dark red blood cells in fluorescently labeled plasma. From the stack of scans repeated at 1,300 Hz, the time-resolved velocity is retrieved using an image correlation approach. Single bifurcation events can be identified from a few fluorescently labeled red blood cells. The applicability of the method for in vivo measurements is illustrated on the basis of two-photon laser scanning microscopy of the cerebral capillary network of mice. Its performance is assessed with synthetic data generated from a two-phase model for the perfusion in a capillary network. The calculation of velocities is found to be sufficiently robust for a wide range of conditions. The achievable limits depend significantly on the experimental conditions and are estimated to be in the 1 μm/s (velocity) and 0.1 s (time resolution) ranges, respectively. Some manual fine-tuning is required for optimal performance in terms of accuracy and time resolution. Further work may lead to improved reliability with which bifurcation events are identified in the algorithm and to include red blood cell flux and hematocrit measurements. With the capability for time-resolved measurements in all vessels of a bifurcation, double-circle scanning trajectories allow a detailed study of the dynamics in vascular networks.

  12. 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.

  13. Predicting stroke outcome using DCE-CT measured blood velocity

    Science.gov (United States)

    Oosterbroek, Jaap; Bennink, Edwin; Dankbaar, Jan Willem; Horsch, Alexander D.; Viergever, Max A.; Velthuis, Birgitta K.; de Jong, Hugo W. A. M.

    2015-03-01

    CT plays an important role in the diagnosis of acute stroke patients. Dynamic contrast enhanced CT (DCE-CT) can estimate local tissue perfusion and extent of ischemia. However, hemodynamic information of the large intracranial vessels may also be obtained from DCE-CT data and may contain valuable diagnostic information. We describe a novel method to estimate intravascular blood velocity (IBV) in large cerebral vessels using DCE-CT data, which may be useful to help predict stroke outcome. DCE-CT scans from 34 patients with isolated M1 occlusions were included from a large prospective multi-center cohort study of patients with acute ischemic stroke. Gaussians fitted to the intravascular data yielded the time-to-peak (TTP) and cerebral-blood-volume (CBV). IBV was computed by taking the inverse of the TTP gradient magnitude. Voxels with a CBV of at least 10% of the CBV found in the arterial input function were considered part of a vessel. Mid-sagittal planes were drawn manually and averages of the IBV over all vessel-voxels (arterial and venous) were computed for each hemisphere. Mean-hemisphere IBV differences, mean-hemisphere TTP differences, and hemisphere vessel volume differences were used to differentiate between patients with good and bad outcome (modified Rankin Scale score <3 versus ≥3 at 90 days) using ROC analysis. AUCs from the ROC for IBV, TTP, and vessel volume were 0.80, 0.67 and 0.62 respectively. In conclusion, IBV was found to be a better predictor of patient outcome than the parameters used to compute it and may be a promising new parameter for stroke outcome prediction.

  14. 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.

  15. 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)

  16. 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....

  17. 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...

  18. 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...

  19. 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

    Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubula...

  20. 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...

  1. 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.

  2. 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)

  3. 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)

  4. 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

  5. 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.

  6. 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

  7. [Coronary artery blood flow velocity non-invasively measured using a vessel-tracking pulsed Doppler system].

    Science.gov (United States)

    Tateishi, O; Aizawa, O; Okamura, T; Yoshida, T; Furuhata, H; Seo, Y; Iinuma, K; Shiki, E

    1988-09-01

    A newly-developed noninvasive method was used to measure left coronary blood flow during phantom experiments. Two techniques were used in which: (1) the sample position can always be set in a fluctuating vessel using a wall echo-tracking method with a phase-locked-loop, and (2) the Doppler reference signal was generated separately synchronous with the wall echo signal. These techniques were combined, using a commercially available pulsed Doppler apparatus (SSH-40B: Toshiba). Basic experiments were performed using a blood vessel phantom to verify the validity of these systems. Blood flow velocity in the fluctuating tube could be measured clearly using a vessel-tracking method. The blood flow velocity of the left anterior descending artery was measured in three normal subjects and in seven patients from the third intercostal space along the left sternal border. The velocity pattern was characterized by a crescendo-decrescendo shape in diastole. The peak velocity which appeared in diastole ranged from 19 to 69 cm/sec, with no difference by disease entity. However, in all cases, the blood flow velocity signals were marred by extraneous signals, making it impossible to measure blood flow velocity during systole. Further improvement of the system is mandatory in order to use this flowmeter clinically.

  8. [Mobile Health: IEEE Standard for Wearable Cuffless Blood Pressure Measuring Devices].

    Science.gov (United States)

    Zhou, Xia; Wu, Wenli; Bao, Shudi

    2015-07-01

    IEEE Std 1708-2014 breaks through the traditional standards of cuff based blood pressure measuring devices and establishes a normative definition of wearable cuffless blood pressure measuring devices and the objective performance evaluation of this kind of devices. This study firstly introduces the background of the new standard. Then, the standard details will be described, and the impact of cuffless blood pressure measuring devices with the new standard on manufacturers and end users will be addressed.

  9. 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 ...

  10. Automated Methods of Corrosion Measurements

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    1997-01-01

    electrochemical measurements as well as elemental analysis look very promising for elucidating corrosion reaction mechanisms. The study of initial surface reactions at the atomic or submicron level is becoming an important field of research in the understanding of corrosion processes. At present, mainly two...... scanning microscope techniques are employed investigating corrosion processes, and usually in situ: in situ scanning tunneling microscopy (in situ STM) and in situ scanning force microscopy (in situ AFM). It is these techniques to which attention is directed here....

  11. 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

    -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 controls......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....... There was no statistical difference in the healthy controls, consistent with previous findings. These results may indicate that the heat-washout method can be used as an alternative to strain gauge blood pressure in the evaluation of peripheral artery disease and wound healing potentials. Furthermore, the heat...

  12. A Reconstruction Method of Blood Flow Velocity in Left Ventricle Using Color Flow Ultrasound.

    Science.gov (United States)

    Jang, Jaeseong; Ahn, Chi Young; Jeon, Kiwan; Heo, Jung; Lee, DongHak; Joo, Chulmin; Choi, Jung-il; Seo, Jin Keun

    2015-01-01

    Vortex flow imaging is a relatively new medical imaging method for the dynamic visualization of intracardiac blood flow, a potentially useful index of cardiac dysfunction. A reconstruction method is proposed here to quantify the distribution of blood flow velocity fields inside the left ventricle from color flow images compiled from ultrasound measurements. In this paper, a 2D incompressible Navier-Stokes equation with a mass source term is proposed to utilize the measurable color flow ultrasound data in a plane along with the moving boundary condition. The proposed model reflects out-of-plane blood flows on the imaging plane through the mass source term. The boundary conditions to solve the system of equations are derived from the dimensions of the ventricle extracted from 2D echocardiography data. The performance of the proposed method is evaluated numerically using synthetic flow data acquired from simulating left ventricle flows. The numerical simulations show the feasibility and potential usefulness of the proposed method of reconstructing the intracardiac flow fields. Of particular note is the finding that the mass source term in the proposed model improves the reconstruction performance. PMID:26078773

  13. A novel method to estimate oxygen saturation of the internal jugular vein blood

    Science.gov (United States)

    Li, Kai; Pan, Boan; Gao, Yuan; Ruan, Zhengshang; Li, Ting

    2016-03-01

    This article introduces a novel method to estimate oxygen saturation of the internal jugular vein blood (SjvO2) by using Near Infrared spectroscopy (NIRS). The different positions of patients can affect the cross-sectional area (CSA) of the internal jugular vein (IJV), in other words, it causes the sectional change of the IJV blood volume. When lying position of patients, the CSA is larger than that keeping upper body 80 degree, and the CSA can compute quantitatively by the use of ultrasound and digital image processing methods. The entire method consist of constructing different position of patient (upper body rotation 0 and 80 degree), comparing the light absorption changes. SjvO2 has been determined from light absorption measurements in two wavelength, before and after the position changes. The method has been applied to the vertical area over the IJV of 11 patients who were placed a central venous catheter into a large vein in the neck for medical uses, using wavelength of 735 and 850 nm. At last, comparing the SjvO2NIRS which measured by NIRS noninvasively with SjvO2IJVBG which was quantified using a whole blood gas analyzer, we found there were some certain relativity. The results were influenced by vascular depth greatly.

  14. 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.)

  15. 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

  16. Normal and system lupus erythematosus red blood cell interactions studied by double trap optical tweezers: direct measurements of aggregation forces

    Science.gov (United States)

    Khokhlova, Maria D.; Lyubin, Eugeny V.; Zhdanov, Alexander G.; Rykova, Sophia Yu.; Sokolova, Irina A.; Fedyanin, Andrey A.

    2012-02-01

    Direct measurements of aggregation forces in piconewton range between two red blood cells in pair rouleau are performed under physiological conditions using double trap optical tweezers. Aggregation and disaggregation properties of healthy and pathologic (system lupus erythematosis) blood samples are analyzed. Strong difference in aggregation speed and behavior is revealed using the offered method which is proposed to be a promising tool for SLE monitoring at single cell level.

  17. Automated measurement of office, home and ambulatory blood pressure in atrial fibrillation.

    Science.gov (United States)

    Kollias, Anastasios; Stergiou, George S

    2014-01-01

    1. Hypertension and atrial fibrillation (AF) often coexist and are strong risk factors for stroke. Current guidelines for blood pressure (BP) measurement in AF recommend repeated measurements using the auscultatory method, whereas the accuracy of the automated devices is regarded as questionable. This review presents the current evidence on the feasibility and accuracy of automated BP measurement in the presence of AF and the potential for automated detection of undiagnosed AF during such measurements. 2. Studies evaluating the use of automated BP monitors in AF are limited and have significant heterogeneity in methodology and protocols. Overall, the oscillometric method is feasible for static (office or home) and ambulatory use and appears to be more accurate for systolic than diastolic BP measurement. 3. Given that systolic hypertension is particularly common and important in the elderly, the automated BP measurement method may be acceptable for self-home and ambulatory monitoring, but not for professional office or clinic measurement. 4. An embedded algorithm for the detection of asymptomatic AF during routine automated BP measurement with high diagnostic accuracy has been developed and appears to be a useful screening tool for elderly hypertensives.

  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. 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)

  20. Measurements of Dynamic Viscoelasticity of Poly (vinyl alcohol) Hydrogel for the Development of Blood Vessel Biomodeling

    Science.gov (United States)

    Kosukegawa, Hiroyuki; Mamada, Keisuke; Kuroki, Kanju; Liu, Lei; Inoue, Kosuke; Hayase, Toshiyuki; Ohta, Makoto

    In vitro blood vessel biomodeling with realistic mechanical properties and geometrical structures is helpful for training in surgical procedures, especial those used in endovascular treatment. Poly (vinyl alcohol) hydrogel (PVA-H), which is made of Poly (vinyl alcohol) (PVA) and water, may be useful as a material for blood vessel biomodeling due to its low surface friction resistance and good transparency. In order to simulate the mechanical properties of blood vessels, measurements of mechanical properties of PVA-H were carried out with a dynamic mechanical analyzer, and the storage modulus (G’) and loss modulus (G”) of PVA-H were obtained. PVA-Hs were prepared by the low-temperature crystallization method. They were made of PVA with various concentrations (C) and degrees of polymerization (DP), and made by blending two kinds of PVA having different DP or saponification values (SV). The G’ and G” of PVA-H increased, as the C or DP of PVA increased, or as the proportion of PVA with higher DP or SV increased. These results indicate that it is possible to obtain PVA-H with desirable dynamic viscoelasticity. Furthermore, it is suggested that PVA-H is stable in the temperature range of 0°C to 40°C, indicating that biomodeling made of PVA-H should be available at 37°C, the physiological temperature. The dynamic viscoelasticity of PVA-H obtained was similar to that of the dog blood vessel measured in previous reports. In conclusion, PVA-H is suggested to be useful as a material of blood vessel biomodeling.

  1. 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.

  2. 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

  3. 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.

  4. Precision of INR measured with a patient operated whole blood coagulometer

    DEFF Research Database (Denmark)

    Attermann, Jørn; Andersen, Niels Trolle; Korsgaard, Helle;

    2003-01-01

    INTRODUCTION: The objective of the present study was to evaluate the precision of a portable whole blood coagulometer (CoaguChek S) in the hands of self-managing patients on oral anticoagulant therapy (OAT). MATERIALS AND METHODS: Fifteen patients on self-managed OAT performed measurements of INR...... by two types of portable whole blood coagulometers (CoaguChek and CoaguChek S) at home for 10 weeks. RESULTS: The coefficient of variation (CV) of INRs determined at home by CoaguChek S by patients on self-managed OAT was 5.5% (95% confidence limits: 4.9%, 6.1%). The biological CV of INR within...... and between patients was 15.0% and 14.7%, respectively. CONCLUSION: The precision of CoaguChek S is satisfactory....

  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)

    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...... 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...

  6. 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.

  7. 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.

  8. 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...

  9. 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

  10. 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.

  11. 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...

  12. 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

  13. Blood volume measurement with indocyanine green pulse spectrophotometry: dose and site of dye administration

    NARCIS (Netherlands)

    M.R. Germans; P.C. de Witt Hamer; L.J. van Boven; K.A.H. Zwinderman; G.J. Bouma

    2010-01-01

    (1) To determine the optimal administration site and dose of indocyanine green (ICG) for blood volume measurement using pulse spectrophotometry, (2) to assess the variation in repeated blood volume measurements for patients after subarachnoid hemorrhage and (3) to evaluate the safety and efficacy of

  14. Methodological aspects of blood pressure measurement and adherence to antihypertensive drug therapy

    NARCIS (Netherlands)

    Braam, R.L.

    2007-01-01

    Hypertension is an important risk-factor for cardiovascular disease. Accurate blood pressure measurements are very important to diagnose hypertension. Nowadays these blood pressure measurements are often performed using automatic devices. One can wonder whether these devices are accurate enough. In

  15. 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

  16. Comparison of three different methods of total carbon dioxide measurement.

    Science.gov (United States)

    Kilborn, Susan H.; Bonnett, Brenda N.; Pook, Harold A.

    1995-01-01

    The objective of this study was to compare total carbon dioxide (TCO(2)) levels measured by three different methods. Two hundred jugular venous blood samples from dogs admitted to the Veterinary Teaching Hospital, Ontario Veterinary College with various clinical disorders were analyzed by the Radiometer blood gas analyzer (BGA) and the Coulter DACOS analyzer. In 70 of these samples, TCO(2) was also measured by the Kodak Ektachem DTE chemistry analyzer. Comparison of the agreement between methods revealed intraclass correlation coefficients (ICC) of 0.63, 0.79, and 0.82 for the DACOS-Ektachem, DACOS-BGA and Ektachem-BGA comparisons, respectively. Evaluation of the effect of storage time on TCO(2) content of stored serum samples measured on the DACOS analyzer revealed a decrease of almost 2 mmol/L and a decrease in the intraclass correlation coefficient values between the DACOS analyzer and other methods after 7 hours storage time. The results of this observational study revealed lower agreement between the three methods in this study than previously reported between other methods of TCO(2) measurement. Possible reasons for the lower than expected agreement in this study included changes in DACOS values because of storage and differences in methodologies between the methods.

  17. 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...

  18. 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

  19. Targeting of blood safety measures to affected areas with ongoing local transmission of malaria.

    Science.gov (United States)

    Domanović, D; Kitchen, A; Politis, C; Panagiotopoulos, T; Bluemel, J; Van Bortel, W; Overbosch, D; Lieshout-Krikke, R; Fabra, C; Facco, G; Zeller, H

    2016-06-01

    An outbreak of locally acquired Plasmodium vivax malaria in Greece started in 2009 and peaked in 2011. Targeting of blood safety measures to affected areas with ongoing transmission of malaria raised questions of how to define spatial boundaries of such an area and when to trigger any specific blood safety measures, including whether and which blood donation screening strategy to apply. To provide scientific advice the European Centre for Disease Prevention and Control (ECDC) organised expert meetings in 2013. The outcomes of these consultations are expert opinions covering spatial targeting of blood safety measures to affected areas with ongoing local transmission of malaria and blood donation screening strategy for evidence of malaria infection in these areas. Opinions could help EU national blood safety authorities in developing a preventive strategy during malaria outbreaks. PMID:27238883

  20. Quantitative measurements of cerebral blood flow in volume imaging PET scanners

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.J.; Shao, L.; Freifelder, R.; Karp, J.S.; Ragland, J.D. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1995-08-01

    Quantitative measurements of Cerebral Blood Flow (CBF) are performed in a volume imaging PET Scanner by means of moderate activity infusions. In equilibrium infusions, activations are measured by scanning over 10 minutes with 16 minute activations. Typical measured whole brain CBF values are 37{+-}8 ml/min/100g, close to the value of 42 ml/min/100g reported by other groups using this method. For ramped infusions, scanning over 4 minutes with 5 minute activations results in whole brain CBFs of 49 {+-} 9 ml/min/100g, close to the Kety and Schmidt value of 50 ml/min/100g. Both equilibrium and ramped infusion methods have been used to study face and word memory in human subjects. Both methods were able to detect significant activations in regions implicated in human memory. The authors conclude that precise quantitation of regional CBF is achieved using both methods, and that ramped infusions also provide accurate measures of CBF. In addition a simplified protocol for ramped infusion studies has been developed. In this method the whole brain tissue time activity curve generated from dynamic scanning is replaced by an appropriately scaled camera coincidence countrate curve. The resulting whole brain CBF values are only 7% different from the dynamic scan and fit results. Regional CBFs (rCBF) may then be generated from the summed image (4.25 minutes) using a count density vs flow lookup table.

  1. 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...... examination sessions using motion-contrast velocimetry and retinal oximetry with vessel diameter corrections. To test oxygen reactivity, participants were examined during normoxia, after 15 min of hyperoxia and finally after 45 min of normoxia. Repeatability was assessed by intraclass correlation coefficients...... retinal arterial oxygen saturation from 95.1 ± 5.0% to 96.6 ± 6.4% (p = 0.038) and increased retinal venous oxygen saturation from 62.9 ± 6.7% to 70.3 ± 7.8% (p = 0.0010). Parameters returned to baseline levels after subsequent normoxia. Saturation and vessel diameter ICCs were 0.88-0.98 (range...

  2. Lack of correlation of glucose levels in filtered blood plasma to density and conductivity measurements.

    Science.gov (United States)

    Gordon, David M; Ash, Stephen R

    2009-01-01

    The purpose of this research project was to determine whether the glucose level of a blood plasma sample from a diabetic patient could be predicted by measuring the density and conductivity of ultrafiltrate of plasma created by a 30,000 m.w. cutoff membrane. Conductivity of the plasma filtrate measures electrolyte concentration and should correct density measurements for changes in electrolytes and water concentration. In vitro studies were performed measuring conductivity and density of solutions of varying glucose and sodium chloride concentrations. Plasma from seven hospitalized patients with diabetes was filtered across a 30,000 m.w. cutoff membrane. The filtrate density and conductivity were measured and correlated to glucose levels. In vitro studies confirmed the ability to predict glucose from density and conductivity measurements, in varying concentrations of glucose and saline. In plasma filtrate, the conductivity and density measurements of ultrafiltrate allowed estimation of glucose in some patients with diabetes but not others. The correlation coefficient for the combined patient data was 0.45 which was significant but only explained 20% of the variability in the glucose levels. Individually, the correlation was significant in only two of the seven patients with correlation coefficients of 0.79 and 0.88. The reasons for lack of correlation are not clear, and cannot be explained by generation of idiogenic osmoles, effects of alcohol dehydrogenase, water intake, etc. This combination of physical methods for glucose measurement is not a feasible approach to measuring glucose in plasma filtrate.

  3. Comparable application of the OCT and Abbe refractometers for measurements of glycated hemoglobin portion in blood

    Science.gov (United States)

    Zhernovaya, Olga S.; Tuchin, Valery V.; Wang, Ruikang K.

    2006-02-01

    It is known that glucose interacts with plasma proteins and hemoglobin in erythrocytes. Glycated (glycosylated) hemoglobin is the result of an irreversible non-enzymatic fixation of glucose on the beta chain of hemoglobin A. The amount of glycated hemoglobin depends on blood glucose concentration and reflects the mean glycemia of about the previous 2-3 months. Glycated hemoglobin is a useful marker for long-term glucose control in diabetic patients. Therefore, the search of quick and high sensitive methods for measurement of glycated hemoglobin portion in blood is important. This study is focused on the determination of refractive index of hemoglobin solution at different glucose concentrations. Measurements were performed using Abbe refractometer at 589 nm and optical coherence tomography (OCT) at 820 nm. The different amount of glucose (from 0 to 1000 mg/dl with a step 100 mg/dl) was added to hemoglobin solution. Theoretical values of refractive index of hemoglobin solutions with glucose were calculated supposing non-interacting hemoglobin and glucose molecules. There is a difference between measured and calculated values of refractive index. This difference is due to glucose binding to hemoglobin. It is shown that the refractive index measurements can be applied for the evaluation of glycated hemoglobin amount.

  4. Method of measuring luminescence of a material

    Science.gov (United States)

    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).

  5. 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

    kept at 10 mmHg during elevation. In these patients, the increase in vascular resistance was significantly less compared with the situation in which venous pressure was 0 mmHg during elevation. The arterial pressure still did not decrease. It is concluded that perfusion pressure in the ischaemic lower......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 popliteal...

  6. 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

  7. 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

  8. Precision of a new bedside method for estimation of the circulating blood volume

    DEFF Research Database (Denmark)

    Christensen, P; Eriksen, B; Henneberg, S W

    1993-01-01

    corresponding to an increase of less than 2% will result in an unacceptable coefficient of variation of repeated estimates. In the experimental study the coefficient of variation of repeated estimates of CBV was determined from duplicate measurements of CBV in nine healthy subjects and in nine intensive care...... patients. The coefficients of variation were 6.2% and 4.7% in healthy and diseased subjects, respectively. Furthermore, the day-to-day variation of the method with respect to the total amount of circulating hemoglobin (nHb) and CBV was determined from duplicate estimates separated by 24-48 h. In conclusion......The present study is a theoretical and experimental evaluation of a modification of the carbon monoxide method for estimation of the circulating blood volume (CBV) with respect to the precision of the method. The CBV was determined from measurements of the CO-saturation of hemoglobin before...

  9. 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.

  10. [Influence of some anesthesiologic methods on blood loss in procedures for voluntary termination of pregnancy].

    Science.gov (United States)

    Venuti, F S; Granese, D; Fattori, A

    1980-03-01

    120 patients in good health, aged 25-38, all in the first trimester of pregnancy, and requesting interruption of pregnancy, were divided into 4 groups and given different types of anesthesia; 1) general anesthesia with volatile anesthetics; 2) general anesthesia without volatile anesthetics; 3) dissociated anesthesia with Ketamin; and, 4) paracervical block with Mepivacain 1%. All interventions were done through curettage, and lasted 7-18 minutes; in all cases blood loss was carefully collected and measured. Minimum amount of bleeding was noted with paracervical block; maximum amount with volatile anesthetics such as ethrane. For every type of anesthesia blood loss increased with age of pregnancy. There were no postoperative complications. As confirmed by the published literature anesthesia by paracervical block is an easy, uncomplicated method, which requires little preparation time and which can be done at low cost.

  11. 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.

  12. 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).

  13. 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

  14. Effect of self-measurement of blood pressure on adherence to treatment in patients with mild-to-moderate hypertension.

    NARCIS (Netherlands)

    Onzenoort, H.A.W. van; Verberk, W.J.; Kroon, A.A.; Kessels, A.G.; Nelemans, P.J.; Kuy, P.H. van der; Neef, C.; Leeuw, P.W. de

    2010-01-01

    BACKGROUND: Poor adherence to treatment is one of the major problems in the treatment of hypertension. Self blood pressure measurement may help patients to improve their adherence to treatment. METHOD: In this prospective, randomized, controlled study coordinated by a university hospital, a total of

  15. 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

  16. 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

  17. 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

  18. 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...

  19. Numerical methods for simulating blood flow at macro, micro, and multi scales.

    Science.gov (United States)

    Imai, Yohsuke; Omori, Toshihiro; Shimogonya, Yuji; Yamaguchi, Takami; Ishikawa, Takuji

    2016-07-26

    In the past decade, numerical methods for the computational biomechanics of blood flow have progressed to overcome difficulties in diverse applications from cellular to organ scales. Such numerical methods may be classified by the type of computational mesh used for the fluid domain, into fixed mesh methods, moving mesh (boundary-fitted mesh) methods, and mesh-free methods. The type of computational mesh used is closely related to the characteristics of each method. We herein provide an overview of numerical methods recently used to simulate blood flow at macro and micro scales, with a focus on computational meshes. We also discuss recent progress in the multi-scale modeling of blood flow.

  20. 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.

  1. 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

  2. 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.

  3. The hydrogen gas clearance method for liver blood flow examination: inhalation or local application of hydrogen?

    Science.gov (United States)

    Metzger, H P

    1989-01-01

    The combined method of hydrogen inhalation and local hydrogen production enable the determination of hepatic blood flow (HBF) and local hepatic blood flow (LHBF). LHBF was registered within a small superficial tissue volume of 0.5 mm in diameter by means of a multi-wire electrode having 200 microns producing and 100 microns measuring wires arranged within less than 300 microns distance between the measuring wires. The feeding current for hydrogen production was 1 microA, the potential less than 10 V. The clearance in response to inhalation was registered by means of the same measuring electrodes within the same tissue volume. Spontaneously breathing rats (Wistar-Frömter strain, 180-230 g bw, N = 19, ketamin-xylazine anesthesia, artificial respiration) showed the following flow values: HBF +/- SD = 0.50 +/- 0.26 ml/g.min, n = 48 registrations; LHBF +/- SD = 4.66 +/- 2.13 ml/g.min, n = 43. The validity of the combined method is demonstrated in the LHBF/HBF graph which summarizes the data of hemorrhagic and control animals, m = 0.1 and yo = 0.001. The correlation coefficient of r = 0.685 shows a reasonable correlation of the combined data despite the wide scattering of the individual values.

  4. 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.

  5. Lack of reproducibility of linkage results in serially measured blood pressure data

    NARCIS (Netherlands)

    Patel, [No Value; Celedon, JC; Weiss, ST; Palmer, LJ

    2003-01-01

    Background: Using the longitudinal Framingham Heart Study data on blood pressure, we analyzed the reproducibility of linkage measures from serial cross-sectional surveys of a defined population by performing genome-wide model-free linkage analyses to systolic blood pressure (SBP) and history of hype

  6. 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...

  7. 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.

  8. 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...

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Ghost Cell Suspensions as Blood Analogue Fluid for Macroscopic Particle Image Velocimetry Measurements.

    Science.gov (United States)

    Jansen, Sebastian V; Müller, Indra; Nachtsheim, Max; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2016-02-01

    Spatially resolved measurement of blood flow is of great interest in the development of artificial blood-carrying devices such as blood pumps, heart valve prostheses, and oxygenators. Particle image velocimetry (PIV) is able to measure instantaneous velocity fields in a plane with high accuracy and is being used more frequently for the development of such devices. However, as this measurement technique is based on optical access, blood flow at physiological hematocrit values is difficult to measure due to its low transparency and multiscattering properties. So far, only very small dimensions (in the range of 400 μm) can be measured using PIV. A suspension of ghost cells (GCs) offers a higher optical transparency than blood while having a similar rheological behavior. In this study, a procedure for the production of GC suspensions containing a very low intracellular hemoglobin concentration is presented. With the help of multiple rounds of controlled cell lysis, the intracellular hemoglobin concentration could be decreased to a point where a standard macroscopic PIV measurement was possible. A velocity profile of a 44% GC suspension in a circular channel with a diameter of 9.5 mm was measured with high spatial resolution. Meanwhile, the rheological behavior was found to be comparable with blood.

  16. 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.

  17. 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;

    2011-01-01

    to 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 emerging tool in the monitoring and characterizing of metastatic cancer....

  18. 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%。

  19. 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.

  20. Advanced Recording and Preprocessing of Physiological Signals. [data processing equipment for flow measurement of blood flow by ultrasonics

    Science.gov (United States)

    Bentley, P. B.

    1975-01-01

    The measurement of the volume flow-rate of blood in an artery or vein requires both an estimate of the flow velocity and its spatial distribution and the corresponding cross-sectional area. Transcutaneous measurements of these parameters can be performed using ultrasonic techniques that are analogous to the measurement of moving objects by use of a radar. Modern digital data recording and preprocessing methods were applied to the measurement of blood-flow velocity by means of the CW Doppler ultrasonic technique. Only the average flow velocity was measured and no distribution or size information was obtained. Evaluations of current flowmeter design and performance, ultrasonic transducer fabrication methods, and other related items are given. The main thrust was the development of effective data-handling and processing methods by application of modern digital techniques. The evaluation resulted in useful improvements in both the flowmeter instrumentation and the ultrasonic transducers. Effective digital processing algorithms that provided enhanced blood-flow measurement accuracy and sensitivity were developed. Block diagrams illustrative of the equipment setup are included.

  1. 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

  2. Survey of blood cultures methods in Italy in 2010

    Directory of Open Access Journals (Sweden)

    Antonio Goglio

    2011-09-01

    Full Text Available Sepsis is a serious clinical condition, associated with high mortality despite advanced modern medical treatment. Traditionally, the detection and identification of bacteria and fungi circulating in the blood-stream is based on blood cultures. A number of factors influence the yield of blood culture, most of them concerning the microbiologist skill and the laboratory organization. In order to collect information about the practices and procedures used for the detection of microrganisms in blood cultures in the italian laboratory (lab, an e-mail with the invitation to participate in the survey was sent to 2000 members of the Italian Association of Clinical Microbiology. Responses were received from 100 lab, located from all over the country (in 18/20 italian regions. The results presented hereby concern specimen collection, culture techniques, rapid identification and susceptibility testing, laboratory organization, relationships with physicians. In summary, most lab use automated systems (96%, the bottles are incubated immediately during public holidays in 72/96 lab (75% and in 49/97 lab at night (50.5%, the lenght of incubation was 5 or 7 days in 93% of the lab, although it is common to extend the incubation period when brucellosis (74 lab, endocarditis (49 lab, systemic mycosis (33 lab is suspected. A wide variety of media are employed for subcultures. All lab process the positive bottles at least once a day, while only in 42 of 81 (51.9% lab the positive blood are processed on holiday. Communication between clinicians and microbiologist include: distribution of specimen collection guidelines (96/100 lab, availability to microbiologist of patients’ clinical situation (77/96 lab, 80.2%, and adding to report the microbiologist’ suggestion (75/98 lab, 76.5%. The results, compared with those collected with a similar questionnaire in 2001, show a greater adherence to guidelines: the number of bottles examined by lab yearly is almost doubled

  3. 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.

  4. New ITF measure method based on fringes

    Science.gov (United States)

    Fang, Qiaoran; Liu, Shijie; Gao, Wanrong; Zhou, You; Liu, HuanHuan

    2016-01-01

    With the unprecedented developments of the intense laser and aerospace projects', the interferometer is widely used in detecting middle frequency indicators of the optical elements, which put forward very high request towards the interferometer system transfer function (ITF). Conventionally, the ITF is measured by comparing the power spectra of known phase objects such as high-quality phase step. However, the fabrication of phase step is complex and high-cost, especially in the measurement of large-aperture interferometer. In this paper, a new fringe method is proposed to measure the ITF without additional objects. The frequency was changed by adjusting the number of fringes, and the normalized transfer function value was measured at different frequencies. The ITF value measured by fringe method was consistent with the traditional phase step method, which confirms the feasibility of proposed method. Moreover, the measurement error caused by defocus was analyzed. The proposed method does not require the preparation of a step artifact, which greatly reduces the test cost, and is of great significance to the ITF measurement of large aperture interferometer.

  5. A new method for angular displacement measurement

    Institute of Scientific and Technical Information of China (English)

    Caini Zhang(张彩妮); Xiangzhao Wang(王向朝)

    2003-01-01

    We describe a new method for angular displacement measurements that is based on a Fabry-Perot inter-ferometer. A measurement accuracy of 10-s rad is obtained by use of the sinusoidal phase modulatinginterferometry. Another Fabry-Perot interferometer is used to obtain the key initial angle of incidence.

  6. 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 ...

  7. 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.

  8. 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 ...

  9. 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

    The authors determined cerebral blood flow (CBF) with magnetic resonance imaging (MRI) of contrast agent bolus passage and compared the results with those obtained by O-15 labeled water (H215O) and positron emission tomography (PET). Six pigs were examined by MRI and PET under normo......- and 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...... 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. Torsion method for measuring piezooptic coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Skab, I.; Smaga, I.; Savaryn, V.; Vasylkiv, Yu.; Vlokh, R. [Institute of Physical Optics, Lviv (Ukraine)

    2011-01-15

    We develop and describe analytically a torsion method for measuring piezooptic coefficients associated with shear stresses. It is shown that the method enables to increase significantly the accuracy of determination of piezooptic coefficients. The method and the appropriate apparatus are verified experimentally on the example of LiNbO{sub 3} crystals. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. 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...

  16. 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....

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Combination of measurements and the BLUE method

    CERN Document Server

    Lista, Luca

    2016-01-01

    The most accurate method to combine measurement from different experiments is to build a combined likelihood function and use it to perform the desired inference. This is not always possible for various reasons, hence approximate methods are often convenient. Among those, the best linear unbiased estimator (BLUE) is the most popular, allowing to take into account individual uncertainties and their correlations. The method is unbiased by construction if the true uncertainties and their correlations are known, but it may exhibit a bias if uncertainty estimates are used in place of the true ones, in particular if those estimated uncertainties depend on measured values. In those cases, an iterative application of the BLUE method may reduce the bias of the combined measurement.

  2. 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...

  3. 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.

  4. 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

  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. 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)

    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 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. 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

  8. 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

  9. 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

  10. 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).

  11. Perfusion MRI (dynamic susceptibility contrast imaging) with different measurement approaches for the evaluation of blood flow and blood volume in human gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, H. (Den Sundhedsfaglige Kandidatuddannelse, Aarhus Universitet Bygning 1264, Aarhus (Denmark); University College Nordjylland, Aalborg (Denmark)), Email: hnt@ucn.dk; Steffensen, E. (Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark)); Larsson, E. M. (Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark); Uppsala University Hospital, Department of Radiology, Uppsala (Sweden))

    2012-02-15

    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 technique arterial spin labelling (ASL) presently provides measurement only of cerebral blood flow (CBF), which has not been widely used in human brain tumor studies. Purpose. To assess if measurement of blood flow is comparable with measurement of blood volume in human biopsy-proven gliomas obtained by DSC-MRI using two different regions for normalization and two different measurement approaches. Material and Methods. Retrospective study of 61 patients with different types of gliomas examined with DSC perfusion MRI. Regions of interest (ROIs) were placed in tumor portions with maximum perfusion on rCBF and rCBV maps, with contralateral normal appearing white matter and cerebellum as reference regions. Larger ROIs were drawn for histogram analyses. The type and grade of the gliomas were obtained by histopathology. Statistical comparison was made between diffuse astrocytomas, anaplastic astrocytomas, and glioblastomas. Results. rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r = 0.60) and to the cerebellum (r = 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated (0.61 < r < 0.93), whereas for kurtosis and peak height, the correlation coefficient was about 0.3 when comparing rCBF and rCBV values for the same reference region. Neither rCBF nor rCBV quantification provided a statistically significant difference between the three types of gliomas. However, both rCBF and rCBV tended to increase with tumor grade and to be lower in patients who had undergone resection/treatment. Conclusion. rCBF measurements normalized to white matter

  12. Ultra-sensitive method for determination of ethanol in whole blood by headspace capillary gas chromatography with cryogenic oven trapping.

    Science.gov (United States)

    Watanabe-Suzuki, K; Seno, H; Ishii, A; Kumazawa, T; Suzuki, O

    1999-04-30

    We have established an ultra-sensitive method for determination of ethanol in whole blood by headspace capillary gas chromatography (GC) with cryogenic oven trapping. After heating a blood sample containing ethanol and isobutyl alcohol (internal standard, IS) in a 7.0-ml vial at 55 degrees C for 15 min, 5 ml of the headspace vapor was drawn into a glass syringe and injected into a GC port. All vapor was introduced into an Rtx-BAC2 wide-bore capillary column in the splitless mode at -60 degrees C oven temperature to trap entire analytes, and then the oven temperature was programmed up to 240 degrees C for GC measurements with flame ionization detection. The present method gave sharp peaks of ethanol and IS, and low background noise for whole blood samples. The mean partition into the gaseous phase for ethanol and IS was 3.06+/-0.733 and 8.33+/-2.19%, respectively. The calibration curves showed linearity in the range 0.02-5.0 microg/ml whole blood. The detection limit was estimated to be 0.01 microg/ml. The coefficients of intra-day and inter-day variation for spiked ethanol were 8.72 and 9.47%, respectively. Because of the extremely high sensitivity, we could measure low levels of endogenous ethanol in whole blood of subjects without drinking. The concentration of endogenous ethanol measured for 10 subjects under uncontrolled conditions varied from 0 to 0.377 microg/ml (mean, 0.180 microg/ml). Data on the diurnal changes of endogenous ethanol in whole blood of five subjects under strict food control are also presented; they are in accordance with the idea that endogenous blood ethanol is of enteric bacterial origin.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. Methods of viscosity measurements in sealed ampoules

    Science.gov (United States)

    Mazuruk, Konstantin

    1999-07-01

    Viscosity of semiconductors and metallic melts is usually measured by oscillating cup method. This method utilizes the melts contained in vacuum sealed silica ampoules, thus the problems related to volatility, contamination, and high temperature and pressure can be alleviate. In a typical design, the time required for a single measurement is of the order of one hour. In order to reduce this time to a minute range, a high resolution angular detection system is implemented in our design of the viscometer. Furthermore, an electromagnet generating a rotational magnetic field (RMF) is incorporated into the apparatus. This magnetic field can be used to remotely and nonintrusively measure the electrical conductivity of the melt. It can also be used to induce a well controlled rotational flow in the system. The transient behavior of this flow can potentially yield of the fluid. Based on RMF implementation, two novel viscometry methods are proposed in this work: a) the transient torque method, b) the resonance method. A unified theoretical approach to the three methods is presented along with the initial test result of the constructed apparatus. Advantages of each of the method are discussed.

  18. 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.

  19. In Vivo Measurements of Blood Hemodynamics in Rat Brain using Diffuse Optical Tomography and Diffuse Correlation Spectroscopy

    Science.gov (United States)

    Durduran, Turgut

    2002-03-01

    Cerebral blood flow (CBF), blood volume (CBV) and tissue averaged blood oxygen saturation (Y_t) are measurable quantities at the basis of functional neuroimaging techniques. The coupling of CBF, CBV and Yt affect the cerebral metabolic rate of oxygen utilization (CMRO_2) and is not yet well understood. CMRO2 is generally estimated from the measured quantities using physiological models. Near infrared spectroscopy and tomography (DOT) are important new methods to measure the temporal evolution of CBV and Yt with low spatial resolution. Diffuse correlation spectroscopy (DCS) can also be used to measure temporal and spatial variations of CBF. DOT and DCS allow minimally-invasive measurements with intact skull. I will present experiments on many physiological models such as hypercapnia, hypoxia, focal ischemia, cortical spreading depression and forepaw stimulation where all three quantities are measured simultaneously. The theoretical background for DOT and DCS measurements and basic image reconstruction as applicable to studies of brain hemodynamics will be outlined. State of the art instrumentation and its ongoing development will be presented. Finally, our spectroscopic and tomographic results from animal models will be shown in detail.

  20. Two-temperature method for measuring emissivity

    Science.gov (United States)

    Watson, K.

    1992-01-01

    Spectral emissivity can be uniquely determined from radiance measurements if the object can be observed at two different temperatures. The advantage of this approach is that the spectral emissivity is determined without a priori assumptions about spectral shape. Because the different temperatures are obtained by observing the scene at two times in the diurnal cycle (optimally after midday and midnight), the method assumes that emissivity is temporally invariant. This is valid for rocks and dry soils, not well established for vegetation, and not true when changes in soil moisture occur between the measurements. Accurate image registration and satisfactory signal:noise are critical factors that limit extensive use of this method. ?? 1992.

  1. 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...

  2. 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.

  3. 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.

  4. A method for calculating regional cerebral blood flow from emission computed tomography of inert gas concentrations

    DEFF Research Database (Denmark)

    Celsis, P; Goldman, T; Henriksen, L;

    1981-01-01

    of four 1 min pictures and using a fixed value for the brain:blood partition coefficient, lambda. The method is essentially based on the bolus distribution principle, and it allows the estimation of blood flow in ischemic areas. Application to positron emission tomography is discussed....

  5. 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

    in 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...

  6. Reference data for distal blood pressure in healthy elderly and middle-aged individuals measured with the strain gauge technique. Part II: Distal blood pressure after exercise

    DEFF Research Database (Denmark)

    Arveschoug, Anne Kirstine; Vammen, Birthe; Yoshinaka, Emmy;

    2008-01-01

    Objective. Distal blood pressure (DBP) determination after an exercise test is used on suspicion of arterial peripheral vascular disease (apvd). In our department. the average age of these patients is about 60 years. The usual reference values for pressures after exercise were based on data...... on age. Material and methods. DBP after exercise was measured using the strain-gauge technique on individuals in two groups: group I comprising 25 healthy persons aged between 61 and 82 years, and group II 14 healthy persons aged between 45 and 58 years. Strict rules of inclusion were followed. Results...

  7. Flow measurements in a blood-perfused collagen vessel using x-ray micro-particle image velocimetry.

    Science.gov (United States)

    Antoine, Elizabeth; Buchanan, Cara; Fezzaa, Kamel; Lee, Wah-Keat; Rylander, M 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 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.

  8. 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.

  9. Healing of ulcers on the feet correlated with distal blood pressure measurements in occlusive arterial disease

    DEFF Research Database (Denmark)

    Holstein, P; Lassen, N A

    1980-01-01

    The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel...... of healing correlated significantly with the three distal blood pressure parameters investigated, the closest correlation being with the SDBP measured at the final examination, i.e. just after healing of the ulcer or just before an inevitable major amputation. Of the 22 cases with SDBP below 20 mmHg only two...... and peripheral neuropathy were frequent in the diabetic group. The data show that the systolic digital blood pressure is a particularly valuable prognostic parameter....

  10. 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 the other fingers was measured using a 24-mm-wide cuff. Blood pressure at the proximal phalanx was higher than that at the intermediate phalanx in all fingers except finger V. The difference of blood pressure values corresponded well with circumference of the finger. In 15 normal subjects, blood pressure...... at the proximal phalanx was compared in fingers I, III, IV, and V, using 16, 20, 24 and 24 mm wide cuffs. Finger blood pressure was closest to arm systolic blood pressure when a 24-mm or 27-mm-wide cuff was used in fingers I, III, and IV, and with a 20-mm-wide cuff in finger V. As the standard deviation...

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

    Science.gov (United States)

    Kamodyová, Natália; Baňasová, Lenka; Janšáková, Katarína; Koborová, Ivana; Tóthová, Ľubomíra; Stanko, Peter; Celec, Peter

    2015-01-01

    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 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.

  12. 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

  13. Comparison of Submental Blood Collection with the Retroorbital and Submandibular Methods in Mice (Mus musculus).

    Science.gov (United States)

    Regan, Rainy D; Fenyk-Melody, Judy E; Tran, Sam M; Chen, Guang; Stocking, Kim L

    2016-01-01

    Nonterminal blood sample collection of sufficient volume and quality for research is complicated in mice due to their small size and anatomy. Large (>100 μL) nonterminal volumes of unhemolyzed or unclotted blood currently are typically collected from the retroorbital sinus or submandibular plexus. We developed a third method-submental blood collection-which is similar in execution to the submandibular method but with minor changes in animal restraint and collection location. Compared with other techniques, submental collection is easier to perform due to the direct visibility of the target vessels, which are located in a sparsely furred region. Compared with the submandibular method, the submental method did not differ regarding weight change and clotting score but significantly decreased hemolysis and increased the overall number of high-quality samples. The submental method was performed with smaller lancets for the majority of the bleeds, yet resulted in fewer repeat collection attempts, fewer insufficient samples, and less extraneous blood loss and was qualitatively less traumatic. Compared with the retroorbital technique, the submental method was similar regarding weight change but decreased hemolysis, clotting, and the number of overall high-quality samples; however the retroorbital method resulted in significantly fewer incidents of insufficient sample collection. Extraneous blood loss was roughly equivalent between the submental and retroorbital methods. We conclude that the submental method is an acceptable venipuncture technique for obtaining large, nonterminal volumes of blood from mice. PMID:27657712

  14. Validation of a blood group genotyping method based on high-resolution melting curve analysis.

    Science.gov (United States)

    Gong, Tianxiang; Hong, Ying; Wang, Naihong; Fu, Xuemei; Zhou, Changhua

    2014-01-01

    The detection of polymorphism is the basis of blood group genotyping and phenotype prediction. Genotyping may be useful to determine blood groups when serologic results are unclear. The development and application of different methods for blood group genotyping may be needed as a substitute for blood group typing. The purpose of this study is to establish an approach for blood group genotyping based on a melting curve analysis of real-time polymerase chain reaction (PCR). Using DNA extracted from whole blood, we developed and validated a DNA typing method for detecting DO*01/DO*02, DO*01/DI*02, LU*01/LU*02, and GYPB*03/GYBP*04 alleles using a melting curve analysis. All assays were confirmed with a commercial reagent containing sequence-specific primers (PCR-SSP), and a cohort of the samples was confirmed with sequencing. Results for all blood groups were within the range of specificity and assay variability. Genotypes of 300 blood donors were fully consistent with PCR-SSP data. The obtained genotype distribution is in complete concordance with existing data for the Chinese population. There are several advantages for this approach of blood group genotyping: lower contamination rates with PCR products in this laboratory, ease of performance, automation potential, and rapid cycling time.

  15. Assessment of the relationship between standard probe and implantable fiber measurements of cortical bone blood flow: a canine study.

    Science.gov (United States)

    Jain, R; Podworny, N; Anderson, G I; Schemitsch, E H

    1996-07-01

    Laser Doppler flowmetry (LDF) has been used to assess cortical bone blood flow in various clinical situations, such as osteomyelitis and osteonecrosis. Standard metal-sheathed probes containing optical fibers, applied to cortical bone for perfusion measurements, require direct exposure of the bone surface for each measurement, making nonanesthetized assessments over time impractical. Implantable optical fibers offer a noninvasive method for evaluating cortical bone perfusion without repeated surgical exposure of the bone after initial surgical implantation of the fibers. In vitro studies have shown the reliability of laser Doppler (LD) fibers compared with those of the standard probe. This investigation studied the relationship between measurements of cortical bone perfusion obtained by implanted optical (LD) fibers and standard (LDF) probes in vivo. Midshaft tibial fractures were created in the right hindlimb of 11 adult, large (>25 kg) dogs and stabilized by low contact-dynamic compression plate fixation. Cortical bone blood flow was measured by LDF using standard probes and implantable fibers at five sites along the tibia prefracture, postfracture, immediately postplate application, and at 10 weeks postplating, immediately prior to euthanasia. The implantable fibers were secured onto the cortical bone via the plate and led through a percutaneous exit site. Histological examination of the inguinal and popliteal lymph nodes and soft tissue surrounding the fibers revealed mild inflammation. No significant correlation of blood flow assessed by the implantable fibers and standard probe occurred immediately postfracture (r 0.62). However, a statistically significant correlation was seen postplate application at one of the measurement sites in the distal fracture fragment (r = 0.78, P fibers remained intact and functional until an average of 3 weeks at which time they either fractured or were removed by the animals. This is the first in vivo study assessing the

  16. 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.

  17. 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...

  18. 血站非检测不合格血液报废的原因与预防措施%Causes and preventive measures ofdetecting unqualified blood scrapped blood non

    Institute of Scientific and Technical Information of China (English)

    尚卢清

    2015-01-01

    Objective: to analyze and evaluate the blood non detecting unqualified blood scrap reason, summing up the relevant preventive measures, in order to reduce the blood bank blood unqualiifed rate and disability rate.Method: select 2013 2014 I stand with the collected blood were 8000 bags and 9000 bags, reasons for detecting unqualiifed blood discarding statistical non, calculate the unqualiifed blood scrap rate.Results: a total of 5062 bags of blood due to the non detecting unqualiifed due to scrap its reasons, including insufifcient blood, blood fat, blood bag, color abnormal blood clots, etc..Conclusion: according to the blood bank blood discarding non unqualiifed phenomenon, blood bank should develop and implement feasible preventive measures, fundamentally reduce unnecessary blood scrap, so as to improve the utilization rate of blood, to ensure that our blood work smoothly.%目的:分析和探讨血站非检测不合格血液报废的原因,总结相关预防措施,以此降低血站所采血液不合格率与报废率。方法选取我站2013年与2014年所采集的血液分别24300袋与25600袋,统计非检测不合格血液报废的原因,计算出不合格血液报废率。结果共有3800袋血液由于非检测不合格导致报废,其原因包括采血量不足、脂肪血、采血袋破损、颜色异常、血凝块等。结论针对血站非检测不合格血液报废现象,血站应制定并实施切实可行的预防措施,从根本上降低不必要的血液报废,从而提高血液利用率,确保我国血站工作顺利进行。

  19. 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

  20. 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

    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...

  1. Cost estimation of hypertension management based on home blood pressure monitoring alone or combined office and ambulatory blood pressure measurements.

    Science.gov (United States)

    Boubouchairopoulou, Nadia; Karpettas, Nikos; Athanasakis, Kostas; Kollias, Anastasios; Protogerou, Athanase D; Achimastos, Apostolos; Stergiou, George S

    2014-10-01

    This study aims at estimating the resources consumed and subsequent costs for hypertension management, using home blood pressure (BP) monitoring (HBPM) alone versus combined clinic measurements and ambulatory blood pressure monitoring (C/ABPM). One hundred sixteen untreated hypertensive subjects were randomized to use HBPM or C/ABPM for antihypertensive treatment initiation and titration. Health resources utilized within 12-months follow-up, their respective costs, and hypertension control were assessed. The total cost of the first year of hypertension management was lower in HBPM than C/ABPM arm (€1336.0 vs. €1473.5 per subject, respectively; P cost was identical in both arms. There was no difference in achieved BP control and drug expenditure (HBPM: €233.1 per subject; C/ABPM: €247.6 per subject; P = not significant), whereas the cost of BP measurements and/or visits was higher in C/ABPM arm (€393.9 vs. €516.9, per patient, respectively P cost for subsequent years (>1) was €348.9 and €440.2 per subject, respectively for HBPM and C/ABPM arm and €2731.4 versus €3234.3 per subject, respectively (P cost than C/ABPM, and the same trend is observed in 5-year projection. The results on the resources consumption can be used to make cost estimates for other health-care systems.

  2. 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 ...

  3. 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

  4. 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...

  5. 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...

  6. 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...

  7. 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

  8. Evaluation of dried blood spots with a multiplex assay for measuring recent HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Kelly A Curtis

    Full Text Available Laboratory-based HIV tests for recent infection (TRIs, which primarily measure a specific serological biomarker(s that distinguishes recent from long-term HIV infection, have facilitated the estimation of population-based incidence. Dried blood spots (DBS on filter paper are an attractive sample source for HIV surveillance, given the simplified and cost-effective methods of specimen collection, storage, and shipment. Here, we evaluated the use of DBS in conjunction with an in-house multiplex TRI, the HIV-1-specific Bio-Plex assay, which measures direct antibody binding and avidity to multiple HIV-1 analytes. The assay performance was comparable between matched plasma and DBS samples from HIV-1 infected individuals obtained from diverse sources. The coefficients of variation, comparing the median antibody reactivity for each analyte between plasma and DBS, ranged from 2.78% to 9.40% and the correlation coefficients between the two sample types ranged from 0.89 to 0.97, depending on the analyte. The correlation in antibody reactivity between laboratory and site-prepared DBS for each analyte ranged from 0.87 to 0.98 and from 0.90 to 0.97 between site-prepared DBS and plasma. The correlation in assay measures between plasma and DBS indicate that the sample types can be used interchangeably with the Bio-Plex format, without negatively impacting the misclassification rate of the assay.

  9. Calculation and verification of blood ethanol measurement uncertainty for headspace gas chromatography.

    Science.gov (United States)

    Sklerov, Jason H; Couper, Fiona J

    2011-09-01

    An estimate was made of the measurement uncertainty for blood ethanol testing by headspace gas chromatography. While uncertainty often focuses on compliance to a single threshold level (0.08 g/100 mL), the existence of multiple thresholds, related to enhanced sentencing, subject age, or commercial vehicle licensure, necessitate the use of an estimate with validity across multiple specification levels. The uncertainty sources, in order of decreasing magnitude, were method reproducibility, linear calibration, recovery, calibrator preparation, reference material, and sample preparation. A large set of reproducibility data was evaluated (n = 15,433) in order to encompass measurement variability across multiple conditions, operators, instruments, concentrations and timeframes. The relative, combined standard uncertainty was calculated as ±2.7%, with an expanded uncertainty of ±8.2% (99.7% level of confidence, k = 3). Bias was separately evaluated through a recovery study using standard reference material from a national metrology institute. The uncertainty estimate was verified through the use of proficiency test (PT) results. Assigned values for PT results and their associated uncertainties were calculated as robust means (x*) and standard deviations (s*) of participant values. Performance scores demonstrated that the uncertainty estimate was appropriate across the full range of PT concentrations (0.010-0.370 g/100 mL). The use of PT data as an empirical estimate of uncertainty was not examined. Until providers of blood ethanol PT samples include details on how an assigned value is obtained along with its uncertainty and traceability, the use of PT data should be restricted to the role of verification of uncertainty estimates.

  10. 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

  11. 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.

  12. 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

  13. The evaluation of blood fow in the face skin by LDF method

    Directory of Open Access Journals (Sweden)

    Lychagov V.V.

    2012-06-01

    Full Text Available

    Aims. The research aimed the studying and optimizing of the possibility of measuring microcirculatory of blood fow in human skin by laser Doppler fowmetry (LDF against the various topographic features of the peripheral blood supply of tissues. Materials and methods. 20 people of the age from 20 to 56 years without signs of skin lesions were examined by the LDF device. The LDF device has two radiation sources in the red light at a wavelength range of 650±30 nm and the near — infrared at a wavelength of 805±50 nm. The radiation was carried out with four receiving fbers arranged at distances of 1, 2, 3 and 4 mm from the illuminating fber. The state of microvasculature was studied at four points of skin — in the middle of the forehead, in the center of the right cheek and the symmetric point on the left cheek and chin area. We calculated the average values of microcirculation, its standard deviation and coeffcient of variation. Conclusions. By varying the distance from the illuminating fber to the receiving fber and the wavelength of incident light the values of the microcirculation in the different areas of healthy skin were estimated by laser Doppler fowmetry method (LDF. Tissue probes, the spatial localization of the LDF signal in the tissues and the effective depth of detection have been estimated by Monte Carlo method. It has been found out during the study that the LDF signal changes are directly related to the structural features of the structure of the microvasculature, the depth and density of functioning capillaries. The given method can be used to diagnose the state of biological object in the normal and pathological conditions, as well as evaluating the effectiveness of the treatment of various dermatoses.

  14. Repeated Blood Pressure Measurements in Childhood in Prediction of Hypertension in Adulthood.

    Science.gov (United States)

    Oikonen, Mervi; Nuotio, Joel; Magnussen, Costan G; Viikari, Jorma S A; Taittonen, Leena; Laitinen, Tomi; Hutri-Kähönen, Nina; Jokinen, Eero; Jula, Antti; Cheung, Michael; Sabin, Matthew A; Daniels, Stephen R; Raitakari, Olli T; Juonala, Markus

    2016-01-01

    Hypertension may be predicted from childhood risk factors. Repeated observations of abnormal blood pressure in childhood may enhance prediction of hypertension and subclinical atherosclerosis in adulthood compared with a single observation. Participants (1927, 54% women) from the Cardiovascular Risk in Young Finns Study had systolic and diastolic blood pressure measurements performed when aged 3 to 24 years. Childhood/youth abnormal blood pressure was defined as above 90th or 95th percentile. After a 21- to 31-year follow-up, at the age of 30 to 45 years, hypertension (>140/90 mm Hg or antihypertensive medication) prevalence was found to be 19%. Carotid intima-media thickness was examined, and high-risk intima-media was defined as intima-media thickness >90th percentile or carotid plaques. Prediction of adulthood hypertension and high-risk intima-media was compared between one observation of abnormal blood pressure in childhood/youth and multiple observations by improved Pearson correlation coefficients and area under the receiver operating curve. When compared with a single measurement, 2 childhood/youth observations improved the correlation for adult systolic (r=0.44 versus 0.35, Pblood pressure. In addition, 2 abnormal childhood/youth blood pressure observations increased the prediction of hypertension in adulthood (0.63 for 2 versus 0.60 for 1 observation, P=0.003). When compared with 2 measurements, third observation did not provide any significant improvement for correlation or prediction (P always >0.05). A higher number of childhood/youth observations of abnormal blood pressure did not enhance prediction of adult high-risk intima-media thickness. Compared with a single measurement, the prediction of adult hypertension was enhanced by 2 observations of abnormal blood pressure in childhood/youth.

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.)

  2. A New Method for Measuring Extragalactic Distances

    CERN Document Server

    Yoshii, Y; Minezaki, T; Koshida, S; Peterson, B A

    2014-01-01

    We have pioneered a new method for the measurement of extragalactic distances. This method uses the time-lag between variations in the short wavelength and long wavelength light from an active galactic nucleus (AGN), based on a quantitative physical model of dust reverberation that relates the time-lag to the absolute luminosity of the AGN. We use the large homogeneous data set from intensive monitoring observations in optical and near-infrared wavelength bands with the dedicated 2-m MAGNUM telescope to obtain the distances to 17 AGNs in the redshift range z=0.0024 to z=0.0353. These distance measurements are compared with distances measured using Cepheid variable stars, and are used to infer that H_0= 73 +- 3 (random) km/s/Mpc. The systematic error in H_0 is examined, and the uncertainty in the size distribution of dust grains is the largest source of the systematic error, which is much reduced for a sample of AGNs for which their parameter values in the model of dust reverberation are individually measured....

  3. Analytical Methods for Uranium Concentration Measurements

    International Nuclear Information System (INIS)

    A survey of analytical procedures for the determination of uranium, as performed for NMM in the United States of America, is presented. Methods are outlined for the measurement of the element in a variety of materials, i.e. ores, concentrates, uranium metal, alloys, ceramics, compounds of uranium, scrap processing solutions, residues, and waste stream products. It is not intended as a complete résumé dealing with the subject, but it does offer measurement methods believed to give precise and accurate results of a high order. Because of the monetary value of the materials, and the transfer activities from one installation to another, involving payments or credits, burn-up charges, use charges, etc., it is essential that such methods are used. Methods of analysis to a large extent are dictated by the types of material to be analysed. The use of gravimetric methods are reviewed pertaining to product materials, which are generally defined as uranium metal, or compounds of the metal, such as oxides, halides, or nitrates. A pyro-hydrolysis technique is included under this heading. Non-volatile metallic impurities are determined spectroscopically, and the gravimetric results are corrected accordingly. Volumetric procedures, the ''workhorse'' methods for determining uranium, are thoroughly explored. The technique is applicable to all types of material, providing the uranium available for measurement is present in milligram quantities. Due to the valence states of uranium, reduction-oxidation schemes are particularly attractive. Dissolution problems, separation of interfering elements, reduction steps, and oxidation titrations of reduced uranium are discussed. The application of certain spectrophotometric and fluorometric procedures for analysing low-grade materials are included. Various separation steps incorporated in the procedures before the determination of uranium are reviewed. Along these lines the utilization of differential colorimetry is examined for determining

  4. Thresholds for Diagnosing Hypertension Based on Automated Office Blood Pressure Measurements and Cardiovascular Risk.

    Science.gov (United States)

    Myers, Martin G; Kaczorowski, Janusz; Paterson, J Michael; Dolovich, Lisa; Tu, Karen

    2015-09-01

    The risk of cardiovascular events in relation to blood pressure is largely based on readings taken with a mercury sphygmomanometer in populations which differ from those of today in terms of hypertension severity and drug therapy. Given replacement of the mercury sphygmomanometer with electronic devices, we sought to determine the blood pressure threshold for a significant increase in cardiovascular risk using a fully automated device, which takes multiple readings with the subject resting quietly alone. Participants were 3627 community-dwelling residents aged >65 years untreated for hypertension. Automated office blood pressure readings were obtained in a community pharmacy with subjects seated and undisturbed. This method for recording blood pressure produces similar readings in different settings, including a pharmacy and family doctor's office providing the above procedures are followed. Subjects were followed for a mean (SD) of 4.9 (1.0) years for fatal and nonfatal cardiovascular events. Adjusted hazard ratios (95% confidence intervals) were computed for 10 mm Hg increments in blood pressure (mm Hg) using Cox proportional hazards regression and the blood pressure category with the lowest event rate as the reference category. A total of 271 subjects experienced a cardiovascular event. There was a significant (P=0.02) increase in the hazard ratio of 1.66 (1.09, 2.54) at a systolic blood pressure of 135 to 144 and 1.72 (1.21, 2.45; P=0.003) at a diastolic blood pressure of 80 to 89. A significant (P=0.03) increase in hazard ratio of 1.73 (1.04, 2.86) occurred with a pulse pressure of 80 to 89. These findings are consistent with a threshold of 135/85 for diagnosing hypertension in older subjects using automated office blood pressure.

  5. 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)

  6. 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.

  7. 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

  8. 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

  9. Modified methods of stellar magnetic field measurements

    CERN Document Server

    Kholtygin, A F

    2013-01-01

    The standard methods of the magnetic field measurement, based on an analysis of the relation between the Stokes $V$-parameter and the first derivative of the total line profile intensity, were modified by applying a linear integral operator $\\hat{L}$ to the both sides of this relation. As the operator $\\hat{L}$, the operator of the wavelet transform with DOG-wavelets is used. The key advantage of the proposed method is an effective suppression of the noise contribution to the line profile and the Stokes parameter $V$. The efficiency of the method has been studied using the model line profiles with various noise contributions. To test the proposed method, the spectropolarimetric observations of the A0-type star $\\alpha^2\\,$ CVn, young O-type star $\\theta^1$ Ori C and A0 supergiant HD 92207 were used. The longitudinal magnetic field strengths for these stars calculated by our method appeared to be in a good agreement with those determined by other methods.

  10. Micro-particle image velocimetry for velocity profile measurements of micro blood flows.

    Science.gov (United States)

    Pitts, Katie L; Fenech, Marianne

    2013-04-25

    Micro-particle image velocimetry (μPIV) is used to visualize paired images of micro particles seeded in blood flows. The images are cross-correlated to give an accurate velocity profile. A protocol is presented for μPIV measurements of blood flows in microchannels. At the scale of the microcirculation, blood cannot be considered a homogeneous fluid, as it is a suspension of flexible particles suspended in plasma, a Newtonian fluid. Shear rate, maximum velocity, velocity profile shape, and flow rate can be derived from these measurements. Several key parameters such as focal depth, particle concentration, and system compliance, are presented in order to ensure accurate, useful data along with examples and representative results for various hematocrits and flow conditions.

  11. 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

  12. 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.

  13. Non-Invasive Glucose Measurement by Use of Metabolic Heat Conformation Method

    Directory of Open Access Journals (Sweden)

    Junfeng Li

    2008-05-01

    Full Text Available A non-invasive glucose measurement system based on the method of metabolic heat conformation (MHC is presented in this paper. This system consists of three temperature sensors, two humidity sensors, an infrared sensor and an optical measurement device. The glucose level can be deduced from the quantity of heat dissipation, blood flow rate of local tissue and degree of blood oxygen saturation. The methodology of the data process and the measurement error are also analyzed. The system is applied in a primary clinical test. Compared with the results of a commercial automated chemistry analyzer, the correlation coefficient of the collected data from the system is 0.856. Result shows that the correlation coefficient improves when the factor of heat dissipated by evaporation of the skin is added in. A non-invasive method of measuring the blood flow rate of local tissue by heat transmission between skin and contacted conductor is also introduced. Theoretical derivation and numerical simulation are completed as well. The so-called normalized difference mean (NDM is chosen to express the quantity of the blood flow rate. The correlation coefficient between the blood flow rates by this method and the results of a Doppler blood flow meter is equal to 0.914.

  14. 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.

  15. 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.

  16. Measurement and Hemodialysis Effect of Complex Relative Permittivity for Blood of Kidney Patients Using Open-Ended Coaxial Measurement Probe

    Science.gov (United States)

    Takeda, Akira; Takata, Kazuyuki; Nagao, Hirotomo; Wang, Jianqing; Fujiwara, Osamu

    Before evaluating the quality of hemodialysis from the limited volume of human blood using a commercially available open-ended coaxial probe, we previously measured the complex relative permittivity of pure water from 200 MHz to 6 GHz with respect to its measured liquid volume, and revealed that 1.9 ml water in a beaker with a diameter of 24 mm and a depth of 2 mm gives a variation within ±0.5 % for the real part and ±7 % for the imaginary part. Based on the above finding, we measured the dielectric properties of 2.5 ml whole blood at 25°C for 10 normal healthy subjects and 9 hemodialysis patients. The measured results on healthy subjects show good agreement with the data reported by Gabriel for human blood at 37°C, while they provide different dispersion characteristics of straight lines for their Cole-Cole plots. The measured results on the patients give further different dispersion characteristics in comparison with the healthy subjects. In order to investigate the above differences statistically, the student t-test was conducted to reveal that permittivity at infinite frequency for the Cole-Cole plots is significantly different with a level of 1 % among its averaged values for normal healthy subjects and patients before dialysis.

  17. 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).

  18. Validity of blood flow measurement using 320 multi-detectors CT and first-pass distribution theory: a phantom study

    Science.gov (United States)

    Chen, Jun; Yu, Xuefang; Xu, Shaopeng; Zhou, Kenneth J.

    2015-03-01

    To evaluate the feasibility of measuring the myocardial blood flow using 320 row detector CT by first-pass technique. Heart was simulated with a container that was filled with pipeline of 3mm diameter; coronary artery was simulated with a pipeline of 2 cm diameter and connected with the simulated heart. The simulated coronary artery was connected with a big container with 1500 ml saline and 150ml contrast agent. One pump linking with simulated heart will withdraw with a speed of 10 ml/min, 15 ml/min, 20 ml/min, 25 ml/min and 30 ml/min. First CT scan starts after 30 s of pumpback with certain speed. The second CT scan starts 5 s after first CT scans. CT images processed as follows: The second CT scan images subtract first CT scan images, calculate the increase of CT value of simulated heart and the CT value of the unit volume of simulated coronary artery and then to calculate the total inflow of myocardial blood flow. CT myocardial blood flows were calculated as: 0.94 ml/s, 2.09 ml/s, 2.74 ml/s, 4.18 ml/s, 4.86 ml/s. The correlation coefficient is 0.994 and r2 = 0.97. The method of measuring the myocardial blood flow using 320 row detector CT by 2 scans is feasible. It is possible to develop a new method for quantitatively and functional assessment of myocardial perfusion blood flow with less radiation does.

  19. 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.

  20. 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.

  1. 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

  2. Large subcriticality measurement by pulsed neutron method

    International Nuclear Information System (INIS)

    To establish the method determining large subcriticalities in the field of nuclear criticality safety, the authors performed pulsed neutron experiments using the Kyoto University Critical Assembly (KUCA) at Research Reactor Institute, Kyoto University and the Cockcroft-Walton type accelerator attached to the assembly. The area-ratio method proposed by Sjoestrand was employed to evaluate subcriticalities from neutron decay curves measured. This method has the shortcomings that the neutron component due to a decay of delayed neutrons remarkably decreases as the subcriticality of an objective increases. To overcome the shortcoming, the authors increased the frequency of pulsed neutron generation. The integral-version of the area-ratio method proposed by Kosaly and Fisher was employed in addition in order to remove a contamination of spatial higher modes from the decay curve. The latter becomes significant as subcriticality increases. The largest subcriticality determined in the present experiments was 125.4 dollars, which was equal to 0.5111 in a multiplication factor. The calculational values evaluated by the computer code KENO-IV with 137 energy groups based on the Monte Carlo method agreed well with those experimental values

  3. Effect of exosome isolation methods on physicochemical properties of exosomes and clearance of exosomes from the blood circulation.

    Science.gov (United States)

    Yamashita, Takuma; Takahashi, Yuki; Nishikawa, Makiya; Takakura, Yoshinobu

    2016-01-01

    Exosomes, which are expected to be delivery systems for biomolecules such as nucleic acids, are collected by several methods. However, the effect of exosome isolation methods on the characteristics of exosomes as drug carriers, such as recovery efficiency after sterile filtration and pharmacokinetics, has not been investigated despite the importance of these characteristics for the development of exosome-based delivery systems. In the present study, exosomes collected from murine melanoma B16-BL6 cells by several methods were compared with respect to dispersibility, recovery rate after filtering, and clearance from the blood circulation in mice. The exosomes were collected by three ultracentrifugation-based methods: simple ultracentrifugation/pelleting (pelleting method), ultracentrifugation with an iodixanol cushion (cushion method), and ultracentrifugation on an iodixanol density gradient (gradient method). The isolation methods had little effect on the particle number of exosomes. In contrast, transmission electron microscopy observation and size distribution measurement using tunable resistive pulse sensing indicated that the exosomes of the gradient method were more dispersed than the others. The exosomes were labeled with Gaussia luciferase and intravenously injected into mice. Clearance of injected exosomes from the blood circulation did not significantly change with isolation methods. When the exosomes were filtered using a 0.2-μm filter, the recovery rate was 82% for the exosomes of the gradient method, whereas it was less than 50% for the others. These results indicate that the exosome isolation method markedly affects the dispersibility and filtration efficiency of the exosomes. PMID:26545617

  4. 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

  5. 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)

  6. 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).

  7. 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,...

  8. 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 ...

  9. A Digital Method for the Detection of Blood Flow Direction in Ultrasonic Doppler Systems

    OpenAIRE

    P. Acevedo–Contla.; M. Barragán–Ocampo.; E. Moreno–Hernández.; F. García–Nocetti.; M. Fuentes–Cruz.; A. Sotomayor–Ortega

    2010-01-01

    Doppler ultrasound systems are widely used to study blood flow and diagnosis of vascular diseases. An important characteristic of these systems is the ability to detect the direction of the blood flow. Most Doppler ultrasound systems apply a quadrature demodulation technique on the ultrasonic transducer output signal. Therefore additional treatment is necessary to separate forward and reverse flow signals. This work presents a digital method to convert signals in quadrature into directional s...

  10. A Simple, Inexpensive and Safe Method for DNA Extraction of Frigid and Clotted Blood Samples

    Directory of Open Access Journals (Sweden)

    Nasrin Mohammadi

    2015-07-01

    Full Text Available Background: Extraction of blood genomicDNAis one of the main approaches for clinical and molecular biology studies. Although several methods have been developed for extraction of blood genomic DNA, most of these methods consume long time and use expensive chemicals such as proteinase K and toxic organic solvent such as phenol and chloroform. The objective of this study was to developed easy and safe method forDNAextraction from clotted and frozen whole blood. This method has many advantages: time reducing, using inexpensive materials, without phenol and chloroform, achieving of high molecular weight and good quality genomicDNA.Materials and Methods: DNA extraction was performed by two methods (new and phenol-chloroform method. Then quantity and quality parameters were evaluated by 1% agarose gel electrophoresis, Nano drop analysis and efficiency of Polymerase Chain Reaction (PCR.Results: Extracted DNA from 500μL of blood samples were 457.7ng/μl and 212ng/μL and their purity (OD260/OD280 were 1.8 and 1.81 for new recommended and phenol–chloroform methods respectively. The PCR results indicated that D16S539 and CSF1PO loci were amplified.Conclusion: These results shown that this method is simple, fast, safe and most economical.

  11. 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...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    . In order to be valid for diagnostic use the patient is required to follow a range of recommendations. However, these recommendations are not always followed. In an observational descriptive study we investigated the effect of introducing active patient guidance by providing contextaware feedback during...... the 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. 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

  14. Low cost subpixel method for vibration measurement

    Science.gov (United States)

    Ferrer, Belen; Espinosa, Julian; Roig, Ana B.; Perez, Jorge; Acevedo, Pablo; Mas, David

    2014-05-01

    Traditional vibration measurement methods are based on devices that acquire local data by direct contact (accelerometers, GPS) or by laser beams (Doppler vibrometers). Our proposal uses video processing to obtain the vibration frequency directly from the scene, without the need of auxiliary targets or devices. Our video-vibrometer can obtain the vibration frequency at any point in the scene and can be implemented with low-cost devices, such as commercial cameras. Here we present the underlying theory and some experiments that support our technique.

  15. Low cost subpixel method for vibration measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ferrer, Belen [Department of Civil Engineering, Univ. Alicante P.O. Box, 99, 03080 Alicante (Spain); Espinosa, Julian; Perez, Jorge; Acevedo, Pablo; Mas, David [Inst. of Physics Applied to the Sciences and Technologies, Univ. Alicante P.O. Box, 99, 03080 Alicante (Spain); Roig, Ana B. [Department of Optics, Univ. Alicante P.O. Box, 99, 03080 Alicante (Spain)

    2014-05-27

    Traditional vibration measurement methods are based on devices that acquire local data by direct contact (accelerometers, GPS) or by laser beams (Doppler vibrometers). Our proposal uses video processing to obtain the vibration frequency directly from the scene, without the need of auxiliary targets or devices. Our video-vibrometer can obtain the vibration frequency at any point in the scene and can be implemented with low-cost devices, such as commercial cameras. Here we present the underlying theory and some experiments that support our technique.

  16. Acoustic levitation methods for density measurements

    Science.gov (United States)

    Trinh, E. H.; Hsu, C. J.

    1986-01-01

    The capability of ultrasonic levitators operating in air to perform density measurements has been demonstrated. The remote determination of the density of ordinary liquids as well as low density solid metals can be carried out using levitated samples with size on the order of a few millimeters and at a frequency of 20 kHz. Two basic methods may be used. The first one is derived from a previously known technique developed for acoustic levitation in liquid media, and is based on the static equilibrium position of levitated samples in the earth's gravitational field. The second approach relies on the dynamic interaction between a levitated sample and the acoustic field. The first technique appears more accurate (1 percent uncertainty), but the latter method is directly applicable to a near gravity-free environment such as that found in space.

  17. Measuring scholarly impact methods and practice

    CERN Document Server

    Rousseau, Ronald; Wolfram, Dietmar

    2014-01-01

    This book is an authoritative handbook of current topics, technologies and methodological approaches that may be used for the study of scholarly impact. The included methods cover a range of fields such as statistical sciences, scientific visualization, network analysis, text mining, and information retrieval. The techniques and tools enable researchers to investigate metric phenomena and to assess scholarly impact in new ways. Each chapter offers an introduction to the selected topic and outlines how the topic, technology or methodological approach may be applied to metrics-related research. Comprehensive and up-to-date, Measuring Scholarly Impact: Methods and Practice is designed for researchers and scholars interested in informetrics, scientometrics, and text mining. The hands-on perspective is also beneficial to advanced-level students in fields from computer science and statistics to information science.

  18. 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 press...

  19. Multivariate evaluation of brain function by measuring regional cerebral blood flow and event-related potentials

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Yoshihiko; Mochida, Masahiko; Shutara, Yoshikazu; Nakagawa, Kazumi [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine; Nagata, Ken

    1998-07-01

    To measure the effect of events on human cognitive function, effects of odors by measurement regional cerebral blood flow (rCBF) and P300 were evaluated during the auditory odd-ball exercise. PET showed the increase in rCBF on the right hemisphere of the brain by coffee aroma. rCBF was measured by PET in 9 of right-handed healthy adults men, and P300 was by event-related potential (ERP) in each sex of 20 right-handed healthy adults. ERP showed the difference of the P300 amplitude between men and women, and showed the tendency, by odors except the lavender oil, that women had higher in the P300 amplitude than men. These results suggest the presence of effects on the cognitive function through emotional actions. Next, the relationship between rCBF and ERP were evaluated. The subjects were 9 of the right-handed healthy adults (average: 25.6{+-}3.4 years old). rCBF by PET and P300 amplitude by ERP were simultaneously recorded during the auditory odd-ball exercise using the tone-burst method (2 kHz of the low frequency aimed stimuli and 1 kHz of the high frequency non-aimed stimuli). The rCBF value was the highest at the transverse gyrus of Heschl and the lowest at the piriform cortex among 24 regions of interest (ROI) from both sides. The difference of P300 peak latent time among ROI was almost the same. The brain waves from Cz and Pz were similar and the average amplitude was highest at Pz. We found the high correlation in the right piriform cortex (Fz), and right (Fz, Cz) and left (Cz, Pz) transverse gyrus of Heschl between the P300 amplitude and rCBF. (K.H.)

  20. Multivariate evaluation of brain function by measuring regional cerebral blood flow and event-related potentials

    International Nuclear Information System (INIS)

    To measure the effect of events on human cognitive function, effects of odors by measurement regional cerebral blood flow (rCBF) and P300 were evaluated during the auditory odd-ball exercise. PET showed the increase in rCBF on the right hemisphere of the brain by coffee aroma. rCBF was measured by PET in 9 of right-handed healthy adults men, and P300 was by event-related potential (ERP) in each sex of 20 right-handed healthy adults. ERP showed the difference of the P300 amplitude between men and women, and showed the tendency, by odors except the lavender oil, that women had higher in the P300 amplitude than men. These results suggest the presence of effects on the cognitive function through emotional actions. Next, the relationship between rCBF and ERP were evaluated. The subjects were 9 of the right-handed healthy adults (average: 25.6±3.4 years old). rCBF by PET and P300 amplitude by ERP were simultaneously recorded during the auditory odd-ball exercise using the tone-burst method (2 kHz of the low frequency aimed stimuli and 1 kHz of the high frequency non-aimed stimuli). The rCBF value was the highest at the transverse gyrus of Heschl and the lowest at the piriform cortex among 24 regions of interest (ROI) from both sides. The difference of P300 peak latent time among ROI was almost the same. The brain waves from Cz and Pz were similar and the average amplitude was highest at Pz. We found the high correlation in the right piriform cortex (Fz), and right (Fz, Cz) and left (Cz, Pz) transverse gyrus of Heschl between the P300 amplitude and rCBF. (K.H.)

  1. Optimized design of a facility for measuring sodium-24 in blood by using Monte Carlo simulations

    Science.gov (United States)

    Yang, Jian-Bo; Li, Rui; Liu, Zhi; Huang, Hong

    2016-04-01

    The Monte Carlo N-Particle Transport Code is adopted for numerical calculations and simulation analyses of the parameters for the designed irradiation facility for human blood (including the neutron moderator and its thickness, the neutron source's location, and the collimator's radius) and of the parameters for the unit for measuring human blood (such as the crystal thickness and radius of NaI) to measure the activity of 24Na in the human body exposed to neutron irradiation in nuclear accidents. Calculation results show that the most suitable parameters for the irradiation facility for human blood include 6-cm polyethylene as the neutron moderator, collimator radius of 7 mm, and a neutron source placed at the bottom of the collimator. However, the parameters for the unit to measure human blood are as follows: both the thickness and the radius of the crystal at the bottom of the NaI detector are 5 cm. The effectiveness of the design parameters was verified by using actual experiments.

  2. Blood flow measurements in selected oral tissues in dogs using radiolabelled microspheres and rubidium-86

    International Nuclear Information System (INIS)

    Radiolabelled microspheres and 86Rb were used in dogs to measure oral tissue blood flow. The tissues studied were mandibular alveolar and basal bone, oral mucosa, gingiva, lip, tongue and soft tissue of hard palate. A suspension of 6 x 106 cerium-141 labelled microspheres, 15 + - 5 μm in diameter was injected into the left ventricle through an arterial catheter in 9 healthy adult dogs. Cardiovascular stability was assessed during the catheterization and injection of microspheres. Following the microsphere injection, 500 μCi of 86Rb was injected intravenously and the animal was killed within 60s. Blood flow measured using 86Rb was not significantly different (p > 0.05) from radiolabelled microsphere flow in mandibular basal bone, oral mucosa and gingiva, suggesting that in these oral tissues nutritional or capillary exchange flow is similar to total blood flow. In mandibular alveolar bone, lip, tongue and soft tissue of hard palate, however, 86Rb measurements were significantly greater (p 86Rb shows promise for continued studies of blood flow in healthy and pathological oral tissues. (author)

  3. Measurement of diabetic sugar concentration in human blood using Raman spectroscopy

    Science.gov (United States)

    Firdous, S.; Nawaz, M.; Ahmed, M.; Anwar, S.; Rehman, A.; Rashid, R.; Mahmood, A.

    2012-06-01

    This study demonstrates the use of Raman spectroscopy for the direct measurement of diabetic sugar in human blood using 532 nm laser system. Raman spectra were collected from whole blood drawn from 21 individuals. We have elicited a reliable glucose signature in diabetic patients, and measured glucose levels in blood serum of normal, healthy diabetic and diabetic patients with other malignancies like cancer and hepatitis. Quantitative predictions of glucose spectra illustrate the predictions based on molecular information carried by the Raman light in highly light-scattering and absorbing media. Raman spectrum peaks for diabetic blood serum are observed at 1168, 1531, 1463, 1021 cm-1 with intensity level 17000 to 18500 pixels attributed to carbohydrates, proteins, lipids, collagen, and skeletal C-C stretch of lipids acyl chains. Raman spectra for normal, diabetic patients having cancer and hepatitis were also recorded. This in vitro glucose monitoring methodology will lead in vivo noninvasive on-line monitoring having painless and at the same time the data will be displayed on-line and in real time. The measured Raman peaks provides detailed bio-chemical fingerprint of the sample and could confer diagnostic benefit in a clinical setting.

  4. 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 ...

  5. Unilateral kidney blood flow measurement using the 81Rb/81mKr ratio.

    NARCIS (Netherlands)

    van Herk, G.; de Zeeuw, D.

    1978-01-01

    A new method has been developed for the continuous quantification of kidney blood flow, utilizing the unique physical and biological properties of the radioactive tracer couple: rubidium-81/krypton-81m. After intravenous injection, 81Rb concentrates primarily in the kidneys, where it continuously ge

  6. Effects of blood sample handling procedures on measurable inflammatory markers in plasma, serum and dried blood spot samples

    DEFF Research Database (Denmark)

    Skogstrand, K.; Thorsen, P.; Vogel, I.;

    2008-01-01

    whole blood samples at low temperatures and rapid isolation of plasma and serum. Effects of different handling procedures for all markers studied are given. DBSS proved to be a robust and convenient way to handle samples for immunoassay analysis of inflammatory markers in whole blood Udgivelsesdato......The interests in monitoring inflammation by immunoassay determination of blood inflammatory markers call for information on the stability of these markers in relation to the handling of blood samples. The increasing use of stored biobank samples for such ventures that may have been collected and...... stored for other purposes, justifies the study hereof. Blood samples were stored for 0, 4, 24, and 48 h at 4 degrees C, room temperature (RT), and at 35 degrees C, respectively, before they were separated into serum or plasma and frozen. Dried blood spot samples (DBSS) were stored for 0, 1, 2, 3, 7, and...

  7. Reproducibility of non-invasive measurement and of short-term variability of blood pressure and heart rate in healthy volunteers.

    OpenAIRE

    Dimier-David, L.; Billon, N; Costagliola, D.; Jaillon, P; Funck-Brentano, C

    1994-01-01

    1. Spectral analyses of blood pressure and heart rate oscillations are increasingly used to assess the influences of diseases and drugs on the autonomic nervous system. Such influences can only be interpreted in view of the spontaneous variability of these oscillations. We therefore studied the reproducibility of power spectral analyses of blood pressure and heart rate fluctuations measured by a non-invasive finger plethysmographic method in 24 healthy volunteers. 2. Intra-observer reproducib...

  8. Telerobotic system performance measurement: motivation and methods

    Science.gov (United States)

    Kondraske, George V.; Khoury, George J.

    1992-11-01

    Telerobotic systems (TRSs) and shared teleautonomous systems result from the integration of multiple sophisticated modules. Procedures used in systems integration design decision-making of such systems are frequently ad hoc compared to more quantitative and systematic methods employed elsewhere in engineering. Experimental findings associated with verification and validation (V&V) are often application-specific. Furthermore, models and measurement strategies do not exist which allow prediction of overall TRS performance in a given task based on knowledge of the performance characteristics of individual subsystems. This paper introduces the use of general systems performance theory (GSPT), developed by the senior author to help resolve similar problems in human performance, as a basis for: (1) measurement of overall TRS performance (viewing all system components, including the operator, as a single entity); (2) task decomposition; (3) development of a generic TRS model; and (4) the characterization of performance of subsystems comprising the generic model. GSPT uses a resource construct to model performance and resource economic principles to govern the interface of systems to tasks. It provides a comprehensive modeling/measurement strategy applicable to complex systems including both human and artificial components. Application is presented in the context of a distributed telerobotics network (Universities Space Automation and Robotics Consortium) as a testbed. Insight into the design of test protocols which elicit application-independent data (i.e., multi-purpose or reusable) is described. Although the work is motivated by space automation and robotics challenges, it is considered to be applicable to telerobotic systems in general.

  9. Characteristic absorption peak of the human blood measured with differential photoacoustic spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new highly sensitive spectroscopy technique- differential photoacoustic spectroscopy (PAS) is presented in this paper. The blood samples from 3 healthy persons, patients with leukemia, patients with pregnancy-induced hypertension (PIH), and 40 patients with nasopharyngeal carcinoma were measured by the PAS technique. The normalized, the first order, and the second order differential photoacoustic spectroscopy of the blood were gained. The results show that (ⅰ) weak absorption peaks or shoulder peaks, which could not be found using conventional photoacoustic spectroscopy, were determined by the first order and the second order differential photoacoustic spectroscopy which significantly improve the sensitivity of detection; and (ii) that two characteristic absorption peaks were found at the wavelength of 637 and 664 nm in all persons' blood samples by the differential photoacoustic spectroscopy technique. This experiment concludes that the differential photoacoustic spectroscopy technique is superior to the conventional photoacoustic spectroscopy technique in detecting photoacoustic spectroscopy of biological samples.

  10. 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

  11. Label-free characterization of white blood cells by measuring 3D refractive index maps

    CERN Document Server

    Yoon, Jonghee; Park, HyunJoo; Choi, Chulhee; Jang, Seongsoo; Park, YongKeun

    2015-01-01

    The characterization of white blood cells (WBCs) is crucial for blood analyses and disease diagnoses. However, current standard techniques rely on cell labeling, a process which imposes significant limitations. Here we present three-dimensional (3D) optical measurements and the label-free characterization of mouse WBCs using optical diffraction tomography. 3D refractive index (RI) tomograms of individual WBCs are constructed from multiple two-dimensional quantitative phase images of samples illuminated at various angles of incidence. Measurements of the 3D RI tomogram of WBCs enable the separation of heterogeneous populations of WBCs using quantitative morphological and biochemical information. Time-lapse tomographic measurements also provide the 3D trajectory of micrometer-sized beads ingested by WBCs. These results demonstrate that optical diffraction tomography can be a useful and versatile tool for the study of WBCs.

  12. In Vivo μPIV Measurements of Blood Flow in Small Vessels of a Rat Model.

    Science.gov (United States)

    Wei, Timothy; Conner, Nadine; Russell, John; Legac, Paul

    2007-11-01

    Ongoing research at the University of Wisconsin Medical School is addressing the effects of perfusion of glottal tissue on voice production. Building on the approach developed by Gharib's group at CalTech for embryonic zebra fish, we have modified μPIV to measure flow in capillaries and small blood vessels in a live rat model. In lieu of seeding particles, the DPIV correlation algorithm tracks the motion of red blood cells moving through these vessels. The methodology will be presented along with a video sequence showing measurements made from muscle tissue laid nominally flat on a microscope stage. Challenges of measurements in three-dimensional geometries, i.e. the throat, will be discussed.

  13. 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.

  14. 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.

  15. Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry.

    Science.gov (United States)

    Alam, Mohammad Afaque; Parks, Cory; Mancarella, Salvatore

    2016-01-01

    During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. Indeed, research focusing on the discovery of new potential therapeutic targets using genetically altered mice requires a reliable, long-term assessment of the systemic arterial pressure variation. Currently, the gold standard for obtaining long-term measurements of blood pressure in ambulatory mice uses implantable radio-transmitters, which require artery cannulation. This technique eliminates the need for tethering, restraining, or anesthetizing the animals which introduce stress and artifacts during data sampling. However, arterial blood pressure monitoring in mice via catheterization can be rather challenging due to the small size of the arteries. Here we present a step-by-step guide to illustrate the crucial key passages for a successful subcutaneous implantation of radio-transmitters and carotid artery cannulation in mice. We also include examples of long-term blood pressure activity taken from freely moving mice after a period of post-surgery recovery. Following this procedure will allow reliable direct blood pressure recordings from multiple animals simultaneously. PMID:27286041

  16. [The net analyte preprocessing combined with radial basis partial least squares regression applied in noninvasive measurement of blood glucose].

    Science.gov (United States)

    Li, Qing-Bo; Huang, Zheng-Wei

    2014-02-01

    In order to improve the prediction accuracy of quantitative analysis model in the near-infrared spectroscopy of blood glucose, this paper, by combining net analyte preprocessing (NAP) algorithm and radial basis functions partial least squares (RBFPLS) regression, builds a nonlinear model building method which is suitable for glucose measurement of human, named as NAP-RBFPLS. First, NAP is used to pre-process the near-infrared spectroscopy of blood glucose, in order to effectively extract the information which only relates to glucose signal from the original near-infrared spectra, so that it could effectively weaken the occasional correlation problems of the glucose changes and the interference factors which are caused by the absorption of water, albumin, hemoglobin, fat and other components of the blood in human body, the change of temperature of human body, the drift of measuring instruments, the changes of measuring environment, and the changes of measuring conditions; and then a nonlinear quantitative analysis model is built with the near-infrared spectroscopy data after NAP, in order to solve the nonlinear relationship between glucose concentrations and near-infrared spectroscopy which is caused by body strong scattering. In this paper, the new method is compared with other three quantitative analysis models building on partial least squares (PLS), net analyte preprocessing partial least squares (NAP-PLS) and RBFPLS respectively. At last, the experimental results show that the nonlinear calibration model, developed by combining NAP algorithm and RBFPLS regression, which was put forward in this paper, greatly improves the prediction accuracy of prediction sets, and what has been proved in this paper is that the nonlinear model building method will produce practical applications for the research of non-invasive detection techniques on human glucose concentrations.

  17. Continuous estimates of dynamic cerebral autoregulation: influence of non-invasive arterial blood pressure measurements

    International Nuclear Information System (INIS)

    Temporal variability of parameters which describe dynamic cerebral autoregulation (CA), usually quantified by the short-term relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), could result from continuous adjustments in physiological regulatory mechanisms or could be the result of artefacts in methods of measurement, such as the use of non-invasive measurements of BP in the finger. In 27 subjects (61 ± 11 years old) undergoing coronary artery angioplasty, BP was continuously recorded at rest with the Finapres device and in the ascending aorta (Millar catheter, BPAO), together with bilateral transcranial Doppler ultrasound in the middle cerebral artery, surface ECG and transcutaneous CO2. Dynamic CA was expressed by the autoregulation index (ARI), ranging from 0 (absence of CA) to 9 (best CA). Time-varying, continuous estimates of ARI (ARI(t)) were obtained with an autoregressive moving-average (ARMA) model applied to a 60 s sliding data window. No significant differences were observed in the accuracy and precision of ARI(t) between estimates derived from the Finapres and BPAO. Highly significant correlations were obtained between ARI(t) estimates from the right and left middle cerebral artery (MCA) (Finapres r = 0.60 ± 0.20; BPAO r = 0.56 ± 0.22) and also between the ARI(t) estimates from the Finapres and BPAO (right MCA r = 0.70 ± 0.22; left MCA r = 0.74 ± 0.22). Surrogate data showed that ARI(t) was highly sensitive to the presence of noise in the CBFV signal, with both the bias and dispersion of estimates increasing for lower values of ARI(t). This effect could explain the sudden drops of ARI(t) to zero as reported previously. Simulated sudden changes in ARI(t) can be detected by the Finapres, but the bias and variability of estimates also increase for lower values of ARI. In summary, the Finapres does not distort time-varying estimates of dynamic CA obtained with a sliding window combined with an ARMA model, but

  18. Simultaneous measurement of 25 inflammatory markers and neurotrophins in neonatal dried blood spots by immunoassay with xMAP technology

    DEFF Research Database (Denmark)

    Skogstrand, Kristin; Thorsen, Poul; Nørgaard-Pedersen, Bent;

    2005-01-01

    BACKGROUND: Inflammatory reactions and other events in early life may be part of the etiology of late-onset diseases, including cerebral palsy, autism, and type 1 diabetes. Most neonatal screening programs for congenital disorders are based on analysis of dried blood spot samples (DBSS), and stored...... on flowmetric Luminex xMAP technology to measure inflammatory markers and neutrophins in DBSS. RESULTS: The high-capacity 25-plex multianalyte method measured 23 inflammatory and trophic cytokines, triggering receptor expressed on myeloid cells-1 (TREM-1), and C-reactive protein in two 3.2-mm punches from DBSS...... in DBSS models was 174%, mean intra- and interassay CVs were 6.2% and 16%, respectively, and the mean correlation between added and measured analytes was r2 = 0.91. In DBSS routinely collected on days 5-7 from 8 newborns with documented inflammatory reactions at birth, the method detected significantly...

  19. Assessing a New Method for Measuring Fetal Exposure to Mercury: Newborn Bloodspots

    Science.gov (United States)

    Nelson, Jessica W.; Edhlund, Betsy L.; Johnson, Jean; Rosebush, Christina E.; Holmquist, Zachary S.; Swan, Shanna H.; Nguyen, Ruby H. N.

    2016-01-01

    Background: Measuring mercury in newborn bloodspots to determine fetal exposures is a novel methodology with many advantages. Questions remain, however, about its reliability as an estimate of newborn exposure to mercury. Methods: We studied mercury concentrations in paired bloodspots and cord blood from a convenience sample of 48 Minnesota women and infants. Results: The limit of detection for bloodspots was higher than for cord blood (0.7 and 0.3 μg/L in bloodspots and cord blood, respectively) with the result that mercury was detected in only 38% of newborn bloodspots compared to 62% of cord blood samples. The geometric mean mercury concentration in cord blood was 0.6 μg/L. Mercury concentrations were almost uniformly lower in bloodspots than in cord blood (mean ratio (±SD) = 0.85 ± 0.4), their mean value was significantly less than that for the cord blood (p = 0.02), and the two methods were highly correlated (r = 0.82). Conclusion: These preliminary findings indicate that newborn bloodspot mercury measurements have utility; however, until bloodspot analyses are more sensitive, they are likely to underestimate in utero exposure. PMID:27409626

  20. [Subjective verbal methods in preoperative measurement of anxiety].

    Science.gov (United States)

    Höfling, S; Hutner, G; Ott, H; Fichte, K; Doenicke, A

    1988-06-01

    The role of preoperative anxiety in perioperative adaptation is viewed in two different ways. Janis suggested that anxiety is a drive that evokes the cognitive work of worrying. Leventhal stresses the importance of coping behavior for adaptation, while anxiety may or may not accompany this coping process. Both theories have empirical support. The aim of this study was to determine whether both theories could show empirical support because the scientists chose different methods: Janis used interviews, Leventhal and Lazarus anxiety scales. The study analyzed the pre- and postoperative emotional reactions of surgical patients with three different methods of anxiety measurement: an anxiety scale, a fear thermometer, and a psychoanalytic interview (Gottschalk-Gleser content analysis method). The different methods were compared and related to the adaptation behavior (Table 3). The data showed a clear interaction between the selected methods and respective theories about the effects of preoperative anxiety on intra- and postoperative adaptation. The anxiety scales showed no correlation with adaptation behavior (blood pressure and heart rate during surgery; postoperative pain medication) and were not related to the anxiety scores obtained from the interview (content analysis). On the other hand, the interview anxiety measurements showed a clear relationship between separation anxiety (and also shame anxiety), physiological excitement during surgery (increase in heart rate), and postoperative medication (increased analgesics and tranquilizers). The patients who worried about the risks of surgery (Verletzungsangst, see Fig. 3) had very good perioperative adjustment, so that the quality of anxiety measured in the interview was very important for the prediction of adaptation. PMID:3407901

  1. Comparison between Digital Image Processing and Spectrophotometric Measurements Methods

    Directory of Open Access Journals (Sweden)

    Bogdan Adnan HAIFA

    2011-03-01

    Full Text Available Background: Spectrophotometer is a very common instrument in various scientific fields and gives accurate information about light absorbance and transmittance through materials using monochromatic light source. Though, devices used in spectrophotometry can be quite expensive, using components with high technical specifications and the procedure itself is time consuming. Regular digital image acquisition instruments like scanners and cameras on the other hand uses very cheap electronic components to record the information on 3 wide band channels (Red, Green, Blue. Purpose: This paper studies the possibility of correlating the measurements from the spectrophotometer with raw data from digital image acquisition instruments. Materials and Methods: Because the results will be used in protein electrophoresis, we prepared o set of plates with blood serum in different dilutions, stained with Coomassie Brilliant Blue. The absorbance of the resulting plates has been measured using a spectrophotometer and after that, the plates were scanned with a regular office scanner. The digital image was converted in different color spaces (gray scale, RGB, HSV, HSL, CIEXYZ and CIELAB using custom developed software in C++. We statistically measured the correlation coefficient of different parameters from the color space with the absorption measured with the spectrophotometer. Results and Discussion: The findings of this work show that a consumer digital scanner can be used as a fast and inexpensive alternative to spectrophotometers. This offers the possibility of using scanned images of protein electrophoresis to make quantitative estimations regarding the proteinogram.

  2. PERT: a method for expression deconvolution of human blood samples from varied microenvironmental and developmental conditions.

    Directory of Open Access Journals (Sweden)

    Wenlian Qiao

    Full Text Available The cellular composition of heterogeneous samples can be predicted using an expression deconvolution algorithm to decompose their gene expression profiles based on pre-defined, reference gene expression profiles of the constituent populations in these samples. However, the expression profiles of the actual constituent populations are often perturbed from those of the reference profiles due to gene expression changes in cells associated with microenvironmental or developmental effects. Existing deconvolution algorithms do not account for these changes and give incorrect results when benchmarked against those measured by well-established flow cytometry, even after batch correction was applied. We introduce PERT, a new probabilistic expression deconvolution method that detects and accounts for a shared, multiplicative perturbation in the reference profiles when performing expression deconvolution. We applied PERT and three other state-of-the-art expression deconvolution methods to predict cell frequencies within heterogeneous human blood samples that were collected under several conditions (uncultured mono-nucleated and lineage-depleted cells, and culture-derived lineage-depleted cells. Only PERT's predicted proportions of the constituent populations matched those assigned by flow cytometry. Genes associated with cell cycle processes were highly enriched among those with the largest predicted expression changes between the cultured and uncultured conditions. We anticipate that PERT will be widely applicable to expression deconvolution strategies that use profiles from reference populations that vary from the corresponding constituent populations in cellular state but not cellular phenotypic identity.

  3. PERT: a method for expression deconvolution of human blood samples from varied microenvironmental and developmental conditions.

    Science.gov (United States)

    Qiao, Wenlian; Quon, Gerald; Csaszar, Elizabeth; Yu, Mei; Morris, Quaid; Zandstra, Peter W

    2012-01-01

    The cellular composition of heterogeneous samples can be predicted using an expression deconvolution algorithm to decompose their gene expression profiles based on pre-defined, reference gene expression profiles of the constituent populations in these samples. However, the expression profiles of the actual constituent populations are often perturbed from those of the reference profiles due to gene expression changes in cells associated with microenvironmental or developmental effects. Existing deconvolution algorithms do not account for these changes and give incorrect results when benchmarked against those measured by well-established flow cytometry, even after batch correction was applied. We introduce PERT, a new probabilistic expression deconvolution method that detects and accounts for a shared, multiplicative perturbation in the reference profiles when performing expression deconvolution. We applied PERT and three other state-of-the-art expression deconvolution methods to predict cell frequencies within heterogeneous human blood samples that were collected under several conditions (uncultured mono-nucleated and lineage-depleted cells, and culture-derived lineage-depleted cells). Only PERT's predicted proportions of the constituent populations matched those assigned by flow cytometry. Genes associated with cell cycle processes were highly enriched among those with the largest predicted expression changes between the cultured and uncultured conditions. We anticipate that PERT will be widely applicable to expression deconvolution strategies that use profiles from reference populations that vary from the corresponding constituent populations in cellular state but not cellular phenotypic identity.

  4. Optical Transcutaneous pCO2 Sensor using Soft Lithography Method for Arterial Blood Gas Analysis

    Science.gov (United States)

    Kang, Byoung-Ho; Kim, Do-Eok; Leem, Myoung-Kun; Kwon, Dae-Hyuk; Lee, Kwang-Man; Kang, Shin-Won

    2008-10-01

    In this study, we carried out development of non-invasive optical transcutaneous partial pressure of carbon dioxide, pCO2, monitoring system. The purpose of this system is to detect CO2 from outer skin, not from the arterial blood-gathering method. There are advantages about a reduction of analysis time and real-time monitoring that this system might be available. The measurement system is composed of the IR lamp, the pyroelectric sensor including a 4.26 μm optical filter, the optical gas reaction chamber and the signal processing circuit. The optical reaction length of chamber was reduced by 1 mm using the soft-lithography method which CO2 is exhausted in human body as we considered. The fabricated pCO2 monitoring system showed linear result of 6.50×10-6 absorbance/ppm sensitivity for CO2 concentration from 0 ˜5,000 ppm by MFC and about 2 seconds of fast response time. The proposed system can be used in the optical biosensor field for the medical diagnosis such as pCO2 monitoring system and environment monitoring systems.

  5. Simulation of Blood Flow at Vessel Bifurcation by Lattice Boltzmann Method

    Science.gov (United States)

    Kang, Xiu-Ying; Liu, Da-He; Zhou, Jing; Jin, Yong-Juan

    2005-11-01

    The application of the lattice Boltzmann method to the large vessel bifurcation blood flow is investigated in a wide range of Reynolds numbers. The velocity, shear stress and pressure distributions at the bifurcation are presented in detail. The flow separation zones revealed with increase of Reynolds number are located in the areas of the daughter branches distal to the outer corners of the bifurcation where some deposition of particular blood components might occur to form arteriosclerosis. The results also demonstrate that the lattice Boltzmann method is adaptive to simulating the flow in larger vessels under a high Reynolds number.

  6. A Digital Method for the Detection of Blood Flow Direction in Ultrasonic Doppler Systems

    Directory of Open Access Journals (Sweden)

    P. Acevedo–Contla.

    2010-01-01

    Full Text Available Doppler ultrasound systems are widely used to study blood flow and diagnosis of vascular diseases. An important characteristic of these systems is the ability to detect the direction of the blood flow. Most Doppler ultrasound systems apply a quadrature demodulation technique on the ultrasonic transducer output signal. Therefore additional treatment is necessary to separate forward and reverse flow signals. This work presents a digital method to convert signals in quadrature into directional signals using a Fast Fourier Transform (FFT approach. Validation of the method has been achieved using simulated Doppler ultrasound signals.

  7. Optical methods for measurements of skin penetration.

    Science.gov (United States)

    Gotter, B; Faubel, W; Neubert, R H H

    2008-01-01

    Fourier transform infrared photoacoustic (PAS), photothermal deflection (PDS) and Raman spectroscopy belong to the modern innovative noninvasive analytical tools that are beginning to be recognized as highly potential techniques for the noninvasive study of biological tissues and human skin under in vivo conditions. They can be applied to obtain information regarding the molecular composition of the skin down to several hundred micrometers below the skin surface. All three methods allow depth-resolved investigations. While PAS and PDS use a frequency modulation of the excitation beam to reach deeper regions in the sample, the principle of confocal Raman microspectroscopy (CRM) is a movement of the specimen in the focal plane. In consideration of depth measurements PAS and PDS complete the applicable spectrum of CRM, since Raman microscopy requires particular transparent materials.

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

    Directory of Open Access Journals (Sweden)

    Adnan F. N Al-azawy

    2011-05-01

    Full Text Available 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 difference mammalian tissues such as fresh or frozen whole blood, kidney, liver, heart, muscles. The description method have many advantages, reducing the time, using inexpensive materials, no phenol, in addition to small amount of mammalian tissue is required (100-200 mg and 2 ml from whole blood. Genomic DNA was obtained having high molecular weight and good quality, shown by agarose gel electrophoresis and spectrophtometric analysis. These results shown that the modified method is simple, fast, safe, most economical, resulting in a high molecular genomic DNA of good quality from several mammalian tissues and can be used in medical laboratories and research centers.

  9. Pose measurement method based on geometrical constraints

    Institute of Scientific and Technical Information of China (English)

    Zimiao Zhang; Changku Sun; Pengfei Sun; Peng Wang

    2011-01-01

    @@ The pose estimation method based on geometric constraints is studied.The coordinates of the five feature points in the camera coordinate system are calculated to obtain the pose of an object on the basis of the geometric constraints formed by the connective lines of the feature points and the coordinates of the feature points on the CCD image plane; during the solution process,the scaling and orthography projection model is used to approximate the perspective projection model.%The pose estimation method based on geometric constraints is studied. The coordinates of the five feature points in the camera coordinate system are calculated to obtain the pose of an object on the basis of the geometric constraints formed by the connective lines of the feature points and the coordinates of the feature points on the CCD image plane; during the solution process, the scaling and orthography projection model is used to approximate the perspective projection model. The initial values of the coordinates of the five feature points in the camera coordinate system are obtained to ensure the accuracy and convergence rate of the non-linear algorithm. In accordance with the perspective projection characteristics of the circular feature landmarks, we propose an approach that enables the iterative acquisition of accurate target poses through the correction of the perspective projection coordinates of the circular feature landmark centers. Experimental results show that the translation positioning accuracy reaches ±0.05 mm in the measurement range of 0-40 mm, and the rotation positioning accuracy reaches ±0.06° in the measurement range of 4°-60°.

  10. Spectrophotometric determination of total proteins in blood plasma: a comparative study among dye-binding methods

    Directory of Open Access Journals (Sweden)

    Dimas Augusto Morozin Zaia

    2005-05-01

    Full Text Available A comparative study between the biuret method (standard method for total proteins and spectrophotometric methods using dyes (Bradford, 3',3",5',5"-tetrabromophenolphthalein ethyl ester-TBPEE, and erythrosin-B was carried out for the determination of total proteins in blood plasma from rats. Bradford method showed the highest sensitivity for proteins and biuret method showed the lowest. For all the methods, the absorbance for different proteins (BSA, casein, and egg albumin was measured and Bradford method showed the lowest variation of absorbance. The concentration of total protein obtained by using Bradford method was not statistically different (p>0.05 from concentration of total protein obtained by the biuret method. But in regard to erythrosin-B and TBPEE methods the concentrations of total protein were statistically different (pA determinação de proteínas totais em plasma sangüíneo é importante em diversas áreas de pesquisa. Um estudo comparativo entre o método de biureto (método padrão para proteínas totais e diversos métodos que utilizam corantes (Bradford, tetrabromofenolftaleína etil éster-TBPEE, e eritrosina-B foi realizado para a determinação de proteínas totais em plasma sangüíneo de ratos. O método de Bradford mostrou a maior sensibilidade para proteínas e o de biureto a menor. Para todos os métodos, as absorbâncias para diferentes proteínas (BSA, caseína, e ovoalbumina foram medidas e o método de Bradford mostrou a menor variação da absorbância. Utilizando o método de Bradford a concentração de proteínas totais obtida não foi estatisticamente diferente (p>0.05 daquela obtida pelo método do biureto. Porém, para os métodos da eritrosina-B e TBPEE as concentrações de proteínas totais foram estatisticamente diferentes (p<0.05 da obtida pelo método de biureto. Portanto o método de Bradford pode ser utilizado no lugar do método de biureto para a determinação de proteínas totais em plasma sangüíneo.

  11. Field methods for measuring concentrated flow erosion

    Science.gov (United States)

    Castillo, C.; Pérez, R.; James, M. R.; Quinton, J. N.; Taguas, E. V.; Gómez, J. A.

    2012-04-01

    Many studies have stressed the importance of gully erosion in the overall soil loss and sediment yield of agricultural catchments, for instance in recent years (Vandaele and Poesen, 1995; De Santisteban et al., 2006; Wu el al, 2008). Several techniques have been used for determining gully erosion in field studies. The conventional techniques involved the use of different devices (i.e. ruler, pole, tape, micro-topographic profilers, total station) to calculate rill and gully volumes through the determination of cross sectional areas and length of reaches (Casalí et al, 1999; Hessel and van Asch, 2003). Optical devices (i.e. laser profilemeters) have also been designed for the purpose of rapid and detailed assessment of cross sectional areas in gully networks (Giménez et al., 2009). These conventional 2d methods provide a simple and un-expensive approach for erosion evaluation, but are time consuming to carry out if a good accuracy is required. On the other hand, remote sensing techniques are being increasingly applied to gully erosion investigation such as aerial photography used for big-scale, long-term, investigations (e.g. Martínez-Casasnovas et al., 2004; Ionita, 2006), airborne and terrestrial LiDAR datasets for gully volume evaluation (James et al., 2007; Evans and Lindsay, 2010) and recently, major advances in 3D photo-reconstruction techniques (Welty et al. 2010, James et al., 2011). Despite its interest, few studies simultaneously compare the accuracies of the range of conventional and remote sensing techniques used, or define the most suitable method for a particular scale, given and time and cost constraints. That was the reason behind the International Workshop Innovations in the evaluation and measurement of rill and gully erosion, held in Cordoba in May 2011 and from which derive part of the materials presented in this abstract. The main aim of this work was to compare the accuracy and time requirements of traditional (2D) and recently developed

  12. Barrier screens: a method to sample blood-fed and host-seeking exophilic mosquitoes

    Directory of Open Access Journals (Sweden)

    Burkot Thomas R

    2013-02-01

    Full Text Available Abstract Background Determining the proportion of blood meals on humans by outdoor-feeding and resting mosquitoes is challenging. This is largely due to the difficulty of finding an adequate and unbiased sample of resting, engorged mosquitoes to enable the identification of host blood meal sources. This is particularly difficult in the south-west Pacific countries of Indonesia, the Solomon Islands and Papua New Guinea where thick vegetation constitutes the primary resting sites for the exophilic mosquitoes that are the primary malaria and filariasis vectors. Methods Barrier screens of shade-cloth netting attached to bamboo poles were constructed between villages and likely areas where mosquitoes might seek blood meals or rest. Flying mosquitoes, obstructed by the barrier screens, would temporarily stop and could then be captured by aspiration at hourly intervals throughout the night. Results In the three countries where this method was evaluated, blood-fed females of Anopheles farauti, Anopheles bancroftii, Anopheles longirostris, Anopheles sundaicus, Anopheles vagus, Anopheles kochi, Anopheles annularis, Anopheles tessellatus, Culex vishnui, Culex quinquefasciatus and Mansonia spp were collected while resting on the barrier screens. In addition, female Anopheles punctulatus and Armigeres spp as well as male An. farauti, Cx. vishnui, Cx. quinquefasciatus and Aedes species were similarly captured. Conclusions Building barrier screens as temporary resting sites in areas where mosquitoes were likely to fly was an extremely time-effective method for collecting an unbiased representative sample of engorged mosquitoes for determining the human blood index.

  13. Development of a wireless blood pressure measuring device with smart mobile device.

    Science.gov (United States)

    İlhan, İlhan; Yıldız, İbrahim; Kayrak, Mehmet

    2016-03-01

    Today, smart mobile devices (telephones and tablets) are very commonly used due to their powerful hardware and useful features. According to an eMarketer report, in 2014 there were 1.76 billion smartphone users (excluding users of tablets) in the world; it is predicted that this number will rise by 15.9% to 2.04 billion in 2015. It is thought that these devices can be used successfully in biomedical applications. A wireless blood pressure measuring device used together with a smart mobile device was developed in this study. By means of an interface developed for smart mobile devices with Android and iOS operating systems, a smart mobile device was used both as an indicator and as a control device. The cuff communicating with this device through Bluetooth was designed to measure blood pressure via the arm. A digital filter was used on the cuff instead of the traditional analog signal processing and filtering circuit. The newly developed blood pressure measuring device was tested on 18 patients and 20 healthy individuals of different ages under a physician's supervision. When the test results were compared with the measurements made using a sphygmomanometer, it was shown that an average 93.52% accuracy in sick individuals and 94.53% accuracy in healthy individuals could be achieved with the new device. PMID:26626086

  14. Dependence of renal blood flow on renal artery stenosis measured using CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Luedemann, Lutz [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Radiotherapy; Nafz, B.; Persson, P. [Charite - Universitaetsmedizin Berlin (Germany). Inst. for Vegetative Physiology; Elsner, F. [Krankenhaus am Urban, Berlin (Germany). Dept. of Anesthesiology; Grosse-Siestrup, C.; Meissler, M. [Charite - Universitaetsmedizin Berlin (Germany). Experimental Animal Unit; Gutberlet, M. [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Univ. Leipzig/ Leipzig Heart Center (Germany). Dept. of Diagnostic and Interventional Radiology; Lengsfeld, P.; Voth, M. [Bayer-Schering Pharma AG, Berlin (Germany). Global Medical Affairs Diagnostic Imaging

    2011-03-15

    The present study investigates the suitability of computed tomography angiography (CTA) depicting the degree of renal artery stenosis for estimating renal blood flow (RBF) in a kidney. Materials and Methods: We investigated renal artery stenosis assessment by CTA in eight adult female hybrid pigs with an ultrasound probe implanted at the renal vein for RBF measurement. An inflatable metal-free cuff was placed around the renal artery to control the RBF. The RBF was then reduced in four steps. For each reduced RBF value and baseline RBF, CTA with a reconstructed slice thickness of 0.625 mm was performed in the arterial phase following injection of 80 ml of nonionic intravenous contrast medium. The radius of the stenotic and non-stenotic renal artery segment was measured in the reconstructed images. Results: A significant linear correlation (p < 0.0001) was found between the relative apparent stenosis (calculated as the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment) and RBF. The linear regression yielded a slope of 0.57 and a y-axis of 24.1 %. A significant linear correlation (p < 0.0001) was also found between the relative true stenosis (the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment at baseline) and the RBF. The linear regression yielded a slope of 0.67 and a y-axis of 13.8 %. Conclusion: The results show that the relative stenosis apparent on CTA differs from the true degree of renal artery stenosis. Nevertheless, the degree of renal artery stenosis determined by CTA provides a reliable estimate of the resulting RBF reduction. (orig.)

  15. Weathering: methods and techniques to measure

    Science.gov (United States)

    Lopez-Arce, P.; Zornoza-Indart, A.; Alvarez de Buergo, M.; Fort, R.

    2012-04-01

    Surface recession takes place when weathered material is removed from the rocks. In order to know how fast does weathering and erosion occur, a review of several methods, analyses and destructive and non-destructive techniques to measure weathering of rocks caused by physico-chemical changes that occur in bedrocks due to salt crystallization, freezing-thaw, thermal shock, influence of water, wind, temperature or any type of environmental agent leading to weathering processes and development of soils, in-situ in the field or through experimental works in the laboratory are addressed. From micro-scale to macro-scale, from the surface down to more in depth, several case studies on in-situ monitoring of quantification of decay on soils and rocks from natural landscapes (mountains, cliffs, caves, etc) or from urban environment (foundations or facades of buildings, retaining walls, etc) or laboratory experimental works, such as artificial accelerated ageing tests (a.a.e.e.) or durability tests -in which one or more than one weathering agents are selected to assess the material behaviour in time and in a cyclic way- performed on specimens of these materials are summarised. Discoloration, structural alteration, precipitation of weathering products (mass transfer), and surface recession (mass loss) are all products of weathering processes. Destructive (SEM-EDX, optical microscopy, mercury intrusion porosimetry, drilling resistance measurement, flexural and compression strength) and Non-destructive (spectrophotocolorimetry, 3D optical surface roughness, Schmidt hammer rebound tester, ultrasound velocity propagation, Nuclear Magnetic Resonance NMR, X ray computed micro-tomography or CT-scan, geo-radar differential global positioning systems) techniques and characterization analyses (e.g. water absorption, permeability, open porosity or porosity accessible to water) to assess their morphological, physico-chemical, mechanical and hydric weathering; consolidation products or

  16. Development of a magnetic separation method to capture sepsis associated bacteria in blood.

    Science.gov (United States)

    Lopes, Ana Luisa Kalb; Cardoso, Josiane; Dos Santos, Fernanda Roberta Correa Cleto; Silva, Ana Claudia Graziani; Stets, Maria Isabel; Zanchin, Nilson Ivo Tonin; Soares, Maurilio José; Krieger, Marco Aurélio

    2016-09-01

    Bloodstream infections are important public health problems, associated with high mortality due to the inability to detect the pathogen quickly in the early stages of infection. Such inability has led to a growing interest in the development of a rapid, sensitive, and specific assay to detect these pathogens. In an effort to improve diagnostic efficiency, we present here a magnetic separation method for bacteria that is based on mutated lysozyme (LysE35A) to capture S. aureus from whole blood. LysE35A-coated beads were able to bind different MSSA and MRSA isolates in the blood and also other six Gram-positive and two Gram-negative species in whole blood. This system was capable to bind bacteria at low concentrations (10CFU/ml) in spiked blood. Samples captured with the mutated lysozyme showed more responsive amplification of the 16S gene than whole blood at concentrations of 10(3)-10(5)CFU. These data demonstrate detection of S. aureus directly in blood samples, without in vitro cultivation. Our results show that capture with LysE35A-coated beads can be useful to develop a point of care diagnostic system for rapid and sensitive detection of pathogens in clinical settings. PMID:27432342

  17. Computational Fluid Dynamics-Based Design Optimization Method for Archimedes Screw Blood Pumps.

    Science.gov (United States)

    Yu, Hai; Janiga, Gábor; Thévenin, Dominique

    2016-04-01

    An optimization method suitable for improving the performance of Archimedes screw axial rotary blood pumps is described in the present article. In order to achieve a more robust design and to save computational resources, this method combines the advantages of the established pump design theory with modern computer-aided, computational fluid dynamics (CFD)-based design optimization (CFD-O) relying on evolutionary algorithms and computational fluid dynamics. The main purposes of this project are to: (i) integrate pump design theory within the already existing CFD-based optimization; (ii) demonstrate that the resulting procedure is suitable for optimizing an Archimedes screw blood pump in terms of efficiency. Results obtained in this study demonstrate that the developed tool is able to meet both objectives. Finally, the resulting level of hemolysis can be numerically assessed for the optimal design, as hemolysis is an issue of overwhelming importance for blood pumps.

  18. The impact of different blood sampling methods on laboratory rats under different types of anaesthesia

    DEFF Research Database (Denmark)

    Toft, Martin Fitzner; Petersen, Mikke Haxø; Dragsted, Nils;

    2006-01-01

    and that it might take an extra hour to recover from it. CO2 anaesthesia seemed unable to prevent the increase in blood pressure and the fluctuations in body temperature induced by blood sampling, and up to 10 h after sampling, the rats were still affected by CO2 anaesthesia. Rats anaesthetized with isoflurane...... to be the method from which rats most rapidly recover when compared with periorbital puncture and tail vein puncture, and that for anaesthesia, isoflurane is recommended in preference to CO2....... for rats sampled from the tail vein, which showed fluctuations in body temperature in excess of 30 h after sampling. Increases in heart rate and blood pressure within the first hours after sampling indicated that periorbital puncture was the method that had the largest acute impact on the rats...

  19. Validation of a continuous penile blood-flow measurement by pulse-volume-plethysmography.

    Science.gov (United States)

    Lavoisier, P; Barbe, R; Gally, M

    2002-04-01

    Today, in the assessment of cavernous artery blood-flow, the most commonly used technique is Doppler ultrasound velocimetry (continuous, pulsed, color-coded or power), which is often considered as the gold standard. Plethysmographic techniques and radioactive tracers have been widely used for the assessment of global penis flow variations but are not adequate for continuous blood-flow measurement. A new pulse-volume plethysmographic (PVP) device using a water-filled penile cuff was employed to assess continuous blood-flow measurement in the penis. Simultaneously Doppler velocity was recorded and served as a gold standard. A penile water-cuff is connected through a pressure tube to a three-way tap. The pulse-volume changes in the penile water-cuff are measured by means of a latex membrane placed over one of the three-way taps. The displacements of the latex are recorded by a photoplethysmograph. The third tap is connected to a 5 l perfusion bag placed 30 cm above the penis so as to maintain constant pressure in the whole device whatever the penis volume. Twenty-four volunteers were tested. The Doppler velocity signal and pulse volume of cavernous arteries were measured simultaneously after PGE1 intra-cavernous injection. Blood-flow variations were induced by increasing penis artery compression with a second penile water-cuff used as a tourniquet fitted onto the penis root, and the pressure of which could be modified by a water-filled syringe. The amplitude of the plethysmographic pulse-volume signal and the area under the Doppler velocity signal were correlated. The inter-patient (n=24) correlation ranged from 0.455 to 0.904, with a mean correlation of 0.704 and P<0.0001. PVP measurement by a water-filled cuff was validated by ultrasound velocimetry. This new continuous, non-invasive and easy-to-use technique enables physiological and physiopathological flow-measurement during sleep, under visual sexual stimulation (VSS), or following artificial erection

  20. Effects of Zinc Supplementation on the Anthropometric Measurements, Lipid Profiles and Fasting Blood Glucose in the Healthy Obese Adults

    Directory of Open Access Journals (Sweden)

    Sepide Mahluji

    2013-02-01

    Full Text Available 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. Anthropometric measurements (body mass index (BMI, weight and waist circumference were recorded before and at the end of study. Lipid profile biomarkers and fasting blood glucose were determined using enzymatic procedure. Analysis of Covariance (ANCOVA test was run to compare the post-treatment values of the two groups, and t-test was conducted to compare within group changes. Results: Serum zinc concentration was increased significantly in intervention group (p=0.024. BMI and body weight was significantly decreased (p=0.030 and p=0.020, respectively. Lipid profile biomarkers and fating blood glucose did not change significantly but triglyceride level was significantly decreased (p=0.006 in the intervention group. Conclusion: The obtained results indicate that zinc supplementation improves BMI, body weight, and triglyceride concentration without considerable effects on lipid profile and glucose level. Zinc can be suggested as a suitable supplementation therapy for obese people, but more studies are needed to verify the results.

  1. On Ultrasonic MTI Measurement of Velocity Profiles in Blood-Flow

    Directory of Open Access Journals (Sweden)

    Bjørn A.J. Angelsen

    1981-04-01

    Full Text Available A theoretical analysis of Doppler frequency estimators proposed to be used in ultrasonic MTI measurements of velocity profiles in blood flow, is given. The estimators give an output in form of a single analogue voltage and the relation of the output to the Doppler spectrum is discussed. Three new estimators are also proposed. All estimators work fairly well for narrow-band Doppler spectra, but errors are found when broad-band spectra are present.

  2. Prognostic significance of distal blood pressure measurements in patients with severe ischaemia

    DEFF Research Database (Denmark)

    Paaske, William; Tønnesen, K H

    1980-01-01

    The clinical course was followed and the ankle and toe blood pressures were measured with the strain gauge technique on 5 occasions during 2 years in 43 patients with pain at rest and/or ischaemic ulceration due to severe ischaemia of the legs on the basis of occlusive arterial disease. Although...... vascular beds, the TPI must change more than 0.15 units from one examination to another before the alteration can be considered significant at the 99% confidence level....

  3. The BUME method: a novel automated chloroform-free 96-well total lipid extraction method for blood plasma[S

    OpenAIRE

    Löfgren, Lars; Ståhlman, Marcus; Forsberg, Gun-Britt; Saarinen, Sinikka; Nilsson, Ralf; Göran I Hansson

    2012-01-01

    Lipid extraction from biological samples is a critical and often tedious preanalytical step in lipid research. Primarily on the basis of automation criteria, we have developed the BUME method, a novel chloroform-free total lipid extraction method for blood plasma compatible with standard 96-well robots. In only 60 min, 96 samples can be automatically extracted with lipid profiles of commonly analyzed lipid classes almost identically and with absolute recoveries similar or better to what is ob...

  4. Comparison of uteroplacental blood flow in normal and pre-eclamptic patients measurement with technetium-99m and a computer-linked gamma camera

    International Nuclear Information System (INIS)

    Uteroplacental blood flow studies in preeclampsia are of special interest since the vascular changes reported in this disease might constitute a structural basis for a reduction of blood flow. Evidence has also been given for a decreased uteroplacental blood flow in preeclampsia. Among the various methods to estimate the maternal placental blood flow, the one most frequently reported in the literature during the last years has been the time activity analysis of short lived radiotracer such as technetium-99m or indium-113m injected intravenously. Only few studies with the above mentioned technique comparing normal and preeclampsia cases have been undertaken. In clinical practice we frequently experience difficuly in finding the optimal time to get the delivery in preeclampsia patients. The aim of this study was first to measure uteroplacental blood flow in preeclamptic pregnancies using a computer-linked gamma camera method for the time-activity analysis of technetium-99m and second to discuss the possibility of clinical application of these measurements for determination of fetal well-being and the timing of the delivery in these patients. Uteroplacental blood flow was measured from 13 preeclamptic patients and 19 pregnancies without any complication after 35 completed weeks of gestation from Jan. 1983 to Sep. 1983 at Obstetrics department of Hanyang University Hospital. (Author)

  5. Comparison of uteroplacental blood flow in normal and pre-eclamptic patients measurement with technetium-99m and a computer-linked gamma camera

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S.H.; Moon, H.; Kim, D.S.; Cho, S.S.

    1985-05-01

    Uteroplacental blood flow studies in preeclampsia are of special interest since the vascular changes reported in this disease might constitute a structural basis for a reduction of blood flow. Evidence has also been given for a decreased uteroplacental blood flow in preeclampsia. Among the various methods to estimate the maternal placental blood flow, the one most frequently reported in the literature during the last years has been the time activity analysis of short lived radiotracer such as technetium-99m or indium-113m injected intravenously. Only few studies with the above mentioned technique comparing normal and preeclampsia cases have been undertaken. In clinical practice we frequently experience difficuly in finding the optimal time to get the delivery in preeclampsia patients. The aim of this study was first to measure uteroplacental blood flow in preeclamptic pregnancies using a computer-linked gamma camera method for the time-activity analysis of technetium-99m and second to discuss the possibility of clinical application of these measurements for determination of fetal well-being and the timing of the delivery in these patients. Uteroplacental blood flow was measured from 13 preeclamptic patients and 19 pregnancies without any complication after 35 completed weeks of gestation from Jan. 1983 to Sep. 1983 at Obstetrics department of Hanyang University Hospital. (Author).

  6. Catecholamine blood test

    Science.gov (United States)

    Norepinephrine -- blood; Epinephrine -- blood; Adrenalin -- blood; Dopamine -- blood ... A blood sample is needed. ... the test. This is especially true if both blood and urine catecholamines are to be measured. You ...

  7. STANDARDIZATION OF GLYCOHEMOGLOBIN RESULTS AND REFERENCE VALUES IN WHOLE-BLOOD STUDIED IN 103 LABORATORIES USING 20 METHODS

    NARCIS (Netherlands)

    WEYKAMP, CW; PENDERS, TJ; MUSKIET, FAJ; VANDERSLIK, W

    1995-01-01

    We investigated the effect of calibration with lyophilized calibrators on whole-blood glycohemoglobin (glyHb) results. One hundred three laboratories, using 20 different methods, determined glyHb in two lyophilized calibrators and two whole-blood samples. For whole-blood samples with low (5%) and hi

  8. Apparatus and method for examining a blood vessel of interest using radiation detected outside the body

    International Nuclear Information System (INIS)

    Stenotic atherosclerotic lesions of the coronary arteries are detected by injecting a number of particulate signal sources such as positron-emitting particles (e.g. gallium 68) into the blood of a subject to determine the velocity of blood flow through the coronary vessels. The particles are tracked in three dimensions whenever they appear in the region of the heart by means of high-resolution high-speed gamma detectors that surround the chest. These recordings of particle position as a function of time are analyzed, and the velocity of blood as it flows through the coronary artery is measured by timing the transit of the particle. From the accumulated data of multiple particle transits through the coronary circulation, a three-dimensional representation of the lumen of the coronary arterial system is constructed

  9. ''Blood flow measurements in the irradiated pig skin using β emitters radionuclides''

    International Nuclear Information System (INIS)

    Non invasive methods of study of the skin blood flow are numerous, but generally do not give any indication on the cutaneous micro-circulatory flow, except for cutaneous laser Doppler. The isotopic exploration of the skin with injected γ radionuclides, even of weak energy, doe snot allow to characterize the skin blood flow, because of the important contribution of the subcutaneous tissues. The use of β emitters energy spectrum, analyzed by different quantitative methods, are proportional to the thickness of the screen localized between the radioactive source and detector. Using simple and complex phantoms composed of tissue equivalent screens, with 32P sources placed at different depths, it was possible to study the degradation of β spectra, simulating respectively the sub-epidermis and sub-dermis vascular levels. A modelization and an experimental study in-vivo are proposed in this work, with 32P phosphate administered intravenously in pigs. (author)

  10. Volumetric measurement of human red blood cells by MOSFET-based microfluidic gate.

    Science.gov (United States)

    Guo, Jinhong; Ai, Ye; Cheng, Yuanbing; Li, Chang Ming; Kang, Yuejun; Wang, Zhiming

    2015-08-01

    In this paper, we present a MOSFET-based (metal oxide semiconductor field-effect transistor) microfluidic gate to characterize the translocation of red blood cells (RBCs) through a gate. In the microfluidic system, the bias voltage modulated by the particles or biological cells is connected to the gate of MOSFET. The particles or cells can be detected by monitoring the MOSFET drain current instead of DC/AC-gating method across the electronic gate. Polystyrene particles with various standard sizes are utilized to calibrate the proposed device. Furthermore, RBCs from both adults and newborn blood sample are used to characterize the performance of the device in distinguishing the two types of RBCs. As compared to conventional DC/AC current modulation method, the proposed device demonstrates a higher sensitivity and is capable of being a promising platform for bioassay analysis. PMID:25349117

  11. Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla

    DEFF Research Database (Denmark)

    Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill;

    2009-01-01

    Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...... imaging of a bolus of a paramagnetic contrast agent passing through the brain. The methods are applied in patients with brain tumors and in healthy subjects. Perfusion was estimated by model-free deconvolution using Tikhonov's method (gray matter/white matter/tumor: 72 +/- 16/30 +/- 8/56 +/- 45 mL/100 g...... on a pixel-by-pixel basis of cerebral perfusion, cerebral blood volume, and blood-brain barrier permeability....

  12. Measuring the costs of retail payment methods

    OpenAIRE

    Fumiko Hayashi; Keeton, William R.

    2012-01-01

    In the last two decades, retail payments have experienced a dramatic shift from paper-based payment methods to electronic methods. Accurate cost information for the two types of methods would help central banks decide how hard to push for a complete transition to electronic methods and which methods to promote. ; To obtain such information, a number of central banks have recently conducted comprehensive studies of the costs of retail payment methods. Differences in the results of these studie...

  13. [Design of Non-Invasive Blood Oxygen Measurement Based on AFE4490].

    Science.gov (United States)

    Zhu, Jinsong; Wu, Shouhao; Guo, Wenxiu; Zheng, Hui; Tang, Dong

    2015-09-01

    From the perspective of portable monitoring devices,we use an analog front-end AFE4490 design a module of Non-invasive blood oxygen measurement, used to collect human pulse wave signal and peak (valley) value detection and then use the principles of non-invasive oximetry calculated oxygen saturation (SPO2). This design of noninvasive oximetry module has the characteristics of small size, low power consumption, and the results of test show that the measurement of oxygen saturation are correct. PMID:26904876

  14. From pioneering to implementing automated blood pressure measurement in clinical practice: Thomas Pickering's legacy

    DEFF Research Database (Denmark)

    Stolarz-Skrzypek, Katarzyna; Thijs, Lutgarde; Wizner, Barbara;

    2010-01-01

    Thomas G. Pickering spent most of his scientific career in carrying out research on clinical hypertension and blood pressure (BP) measurement. In our review of Pickering's seminal work, we first focused on white-coat hypertension and masked hypertension, two terms that he had introduced. Next, we...... involving white-coat hypertension and masked hypertension, diurnal BP variability, and self-measured BP. Recent studies validated Pickering's observations in terms of cardiovascular outcome and bridged the path from concept to application in clinical practice....

  15. Measurement of tissue optical properties with optical coherence tomography: Implication for noninvasive blood glucose concentration monitoring

    Science.gov (United States)

    Larin, Kirill V.

    Approximately 14 million people in the USA and more than 140 million people worldwide suffer from diabetes mellitus. The current glucose sensing technique involves a finger puncture several times a day to obtain a droplet of blood for analysis. There have been enormous efforts by many scientific groups and companies to quantify glucose concentration noninvasively using different optical techniques. However, these techniques face limitations associated with low sensitivity, accuracy, and insufficient specificity of glucose concentrations over a physiological range. Optical coherence tomography (OCT), a new technology, is being applied for noninvasive imaging in tissues with high resolution. OCT utilizes sensitive detection of photons coherently scattered from tissue. The high resolution of this technique allows for exceptionally accurate measurement of tissue scattering from a specific layer of skin compared with other optical techniques and, therefore, may provide noninvasive and continuous monitoring of blood glucose concentration with high accuracy. In this dissertation work I experimentally and theoretically investigate feasibility of noninvasive, real-time, sensitive, and specific monitoring of blood glucose concentration using an OCT-based biosensor. The studies were performed in scattering media with stable optical properties (aqueous suspensions of polystyrene microspheres and milk), animals (New Zealand white rabbits and Yucatan micropigs), and normal subjects (during oral glucose tolerance tests). The results of these studies demonstrated: (1) capability of the OCT technique to detect changes in scattering coefficient with the accuracy of about 1.5%; (2) a sharp and linear decrease of the OCT signal slope in the dermis with the increase of blood glucose concentration; (3) the change in the OCT signal slope measured during bolus glucose injection experiments (characterized by a sharp increase of blood glucose concentration) is higher than that measured in

  16. Quantitation of contact allergy in guinea pigs by measuring changes in skin blood flow and skin fold thickness

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Staberg, B

    1985-01-01

    Skin blood flow determined by laser Doppler flowmetry (LDF) and skin fold thickness (SFT) have been used to quantitate allergic contact dermatitis in the guinea pig maximization test (GPMT) using chlorocresol as the allergen. The closed patch test procedure itself influenced both LDF and SFT...... measurements when determined in 12 sham-treated guinea pigs. The LDF was maximal at 24 hours and the SFT at 48 hours. Before correlating the quantitative measurements with the conventional visual scoring in test and control animals the value from a nearby control site was subtracted from the test site values....... The correlations were highly significant (p less than 0.001-0.05) indicating that the quantitative methods were useful supplements to the visual scoring as a measure of interobserver and interlaboratory differences....

  17. Comparison of reduced models for blood flow using Runge-Kutta discontinuous Galerkin methods

    CERN Document Server

    Puelz, Charles; Canic, Suncica; Rusin, Craig G

    2015-01-01

    Reduced, or one-dimensional blood flow models take the general form of nonlinear hyperbolic systems, but differ greatly in their formulation. One class of models considers the physically conserved quantities of mass and momentum, while another class describes mass and velocity. Further, the averaging process employed in the model derivation requires the specification of the axial velocity profile; this choice differentiates models within each class. Discrepancies among differing models have yet to be investigated. In this paper, we systematically compare several reduced models of blood flow for physiologically relevant vessel parameters, network topology, and boundary data. The models are discretized by a class of Runge-Kutta discontinuous Galerkin methods.

  18. Skin blood flow changes in anaesthetized humans: comparison between skin thermal clearance and finger pulse amplitude measurement.

    Science.gov (United States)

    Saumet, J L; Leftheriotis, G; Dittmar, A; Delhomme, G; Degoute, C S

    1986-01-01

    The effect of general anaesthesia on skin blood flow in the left hand, measured by a new non-invasive probe using the thermal clearance method was examined. A mercury silastic gauge was placed around the third left finger and the plethysmographic wave amplitude was recorded to measure changes in finger pulse amplitude. Heart rate (HR), mean arterial blood pressure (MABP) and skin temperature were also recorded. General anaesthesia was induced by droperidol and phenoperidine injection and propanidid infusion in eight female patients. Skin thermal clearance, plethysmographic wave amplitude, HR, MABP and skin temperature were 0.40 +/- 0.02 w X m-1 degree C-1, 9 +/- 1 mm, 98 +/- 5 beats X min-1, 12.50 +/- 0.93 kPa and 33.3 +/- 3.4 degrees C respectively. The minimal value of MABP was 9.58 +/- 1.06 kPa, whereas skin thermal clearance, plethysmographic wave amplitude, HR and skin temperature increased to 0.45 +/- 0.02 w X m-1 degree C-1, 29 +/- 3 mm, 110 +/- 4 beats X min-1 and 34.4 +/- 0.4 degrees C. Changes in skin thermal clearance correlated well with plethysmographic wave amplitude. Statistically significant changes in these two parameters occurred before significant change in HR, MABP or skin temperature. The results show that the new non-invasive probe using the thermal clearance method appears to be a useful device for measuring cutaneous microcirculation in anaesthetized humans, and responds more quickly than change in skin temperature, which is a delayed effect of skin blood flow change. Our results also show that the intensity of cutaneous vasodilatation induced by general anaesthesia did not relate to the vascular tone before anaesthesia.

  19. Determination of optimal sampling times for a two blood sample clearance method using (51)Cr-EDTA in cats.

    Science.gov (United States)

    Vandermeulen, Eva; De Sadeleer, Carlos; Piepsz, Amy; Ham, Hamphrey R; Dobbeleir, André A; Vermeire, Simon T; Van Hoek, Ingrid M; Daminet, Sylvie; Slegers, Guido; Peremans, Kathelijne Y

    2010-08-01

    Estimation of the glomerular filtration rate (GFR) is a useful tool in the evaluation of kidney function in feline medicine. GFR can be determined by measuring the rate of tracer disappearance from the blood, and although these measurements are generally performed by multi-sampling techniques, simplified methods are more convenient in clinical practice. The optimal times for a simplified sampling strategy with two blood samples (2BS) for GFR measurement in cats using plasma (51)chromium ethylene diamine tetra-acetic acid ((51)Cr-EDTA) clearance were investigated. After intravenous administration of (51)Cr-EDTA, seven blood samples were obtained in 46 cats (19 euthyroid and 27 hyperthyroid cats, none with previously diagnosed chronic kidney disease (CKD)). The plasma clearance was then calculated from the seven point blood kinetics (7BS) and used for comparison to define the optimal sampling strategy by correlating different pairs of time points to the reference method. Mean GFR estimation for the reference method was 3.7+/-2.5 ml/min/kg (mean+/-standard deviation (SD)). Several pairs of sampling times were highly correlated with this reference method (r(2) > or = 0.980), with the best results when the first sample was taken 30 min after tracer injection and the second sample between 198 and 222 min after injection; or with the first sample at 36 min and the second at 234 or 240 min (r(2) for both combinations=0.984). Because of the similarity of GFR values obtained with the 2BS method in comparison to the values obtained with the 7BS reference method, the simplified method may offer an alternative for GFR estimation. Although a wide range of GFR values was found in the included group of cats, the applicability should be confirmed in cats suspected of renal disease and with confirmed CKD. Furthermore, although no indications of age-related effect were found in this study, a possible influence of age should be included in future studies. PMID:20452793

  20. Study on measurement of free ligand concentration in blood and quantitative analysis of brain benzodiazepine receptor

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Kenji; Goromaru, Tsuyoshi; Inoue, Osamu; Itoh, Takashi; Yamasaki, Toshiro.

    1988-11-01

    We developed the method to determine rapidly the free ligand concentration in the blood as an input function for the purpose of quantitative analysis of binding potential (B/sub max//K/sub d/) of brain benzodiazepine receptor in vivo. It was found that the unmetabolized radioligand in the blood after intravenous administration of /sup 3/H-Ro 15 - 1788 could be extracted by chloroform, whereas the radioactive metabolites could not be extracted. And the plasma protein binding of /sup 3/H-Ro 15 - 1788 was determined using an ultrafiltration method. The biodistribution of /sup 3/H-Ro 15 - 1788 in the cerebral cortex, cerebellum and pons-medulla after intravenous administration of the radiotracer in the control and forced-swimmed mice was examined. And the time course of the free ligand concentration in the blood was determined as described above. Further, the binding potential of benzodiazepine receptor in the mouse brain was analyzed using a simple mathematical model. It was suggested that the binding potential of benzodiazepine receptor in the mouse brain was significantly decreased by forced-swimming. In conclusion, it was found that these methods would be useful for quantitative analysis of clinical data in the human brain using /sup 11/C-Ro 15 - 1788 and positron emission tomography (PET).

  1. Measurement of regional cerebral blood flow by intravenous administation of 133 xenon

    International Nuclear Information System (INIS)

    Reviewing the background and the theory for rCFB measurements the following conditions are established for the use of flow measurement with 133-Xenon as a reliable indicator for indirect measurements of cerebral functional activity. 1. There is a strict coupling between rCBF and regional metabolism. This condition can only be considered to be fulfilled in the normal non-anoxic bran tissue. 2. There is a close correlation between the tissue and the venous concentration of 133-Xenin which can be reliably approximated by the blood-brain partition coefficient. This condition can be considered to be fullfilled in the normal flow range, but not in pathological conditions such as cerebrovascular occlusions. 3. Intercompartment diffusion of 133-Xenon has no significant effect upon the measurement of rCBF values. This condition appear to share its limitations for fulfilement with condition 2. 4. There is no significant contamination by the extracerebral flow components at IH or IV rCBF measurements. 5. There is a negligible 'look through' effect from surrounding areas to region with focal high or low blood flow. (U.W.)

  2. ORAL TRANSMUCOSAL BACK PERMEATION OF ALFENTANIL IN DOGS A NOVEL METHOD TO DETERMINE BLOOD ALFENTANIL CONCENTRATION

    Institute of Scientific and Technical Information of China (English)

    牛苏毅; 张洁; 黄宇光

    1994-01-01

    This study explores a novel noninvasivc method for monitoring blood alfentanil concentrations using a dog model. Alfentanil which "back" permeated across the oral muccssa from the systemic circulation was collvcted from the oral mugosal surface and quantitated. The levels of the "back" permeated affentanil were found to closely reflect real time serum affentanfl concentrati~. With Rurther work, this finding may lead to a novel noninvasive method for mollitoring real time serum alfentanil concentrations in its clinical applications.

  3. Effect of Different Blood Sampling Methods on Blood Lead Detection%不同采血方法对血铅检测结果的影响

    Institute of Scientific and Technical Information of China (English)

    周宇华; 海日姑·加帕

    2015-01-01

    目的:探究不同采血方法对血铅检测结果的影响。方法选取2013年3月-2015年3月前来该中心进行职业性健康检查的工人及其子女120名作为研究对象,并于同时期采集工人的静脉血与手指末梢血,对其中的血铅含量进行检测。结果所有受检工人中,手指血与静脉血的血铅含量平均为77μg/L和58μg/L,A、B、C 3组受检工人中手指末端血与静脉血中的血铅含量比较差异有统计学意义(P0.05)。结论在采血过程中,对血液中铅含量的影响因素很多,对静脉血进行采血可以有效提高检测结果的准确性,应引起采血检测人员的高度重视。%Objective To explore the effect of different blood sampling methods on blood lead detection results. Methods In 2013 March 2015 March came to my center for occupational health examination of workers and their children 120 as the research object and at the same time acquisition workers venous blood and peripheral finger blood, on the blood lead levels were detected. Results All the workers under the test, blood lead content in finger blood and venous blood in average 77μg/L and 58μg/L, a, B, C three groups by workers in finger tip blood and venous blood in the blood lead content difference was significant (P0.05). Conclusion In blood of the influencing factors of blood lead levels many, on venous blood can effectively improve the accuracy of detection results, which should be attached great importance to the blood testing personnel.

  4. Evaluation of copper(II)-pyruvaldehyde bis (N-4-methylthiosemicarbazone) for tissue blood flow measurement using a trapped tracer model

    International Nuclear Information System (INIS)

    We have investigated the application of a simple trapped tracer model to measurements of tissue 64Cu-PTSM uptake combined with continuous arterial sampling. A dual-tracer method was used to compare blood flow estimated by 64Cu-PTSM with values derived from measurements using cobalt-57 microspheres in the rat. Prolonged retention of 64Cu-PTSM following intravenous administration was initially confirmed in both normal tissues and tumours. After intraventricular 64Cu-PTSM infusion, cumulative arterial 64Cu activity increased progressively, and after extraction in n-octanol was found to plateau to levels corresponding with those reached following administration of 57Co microspheres. Rapid and species-dependent rates of 64Cu-PTSM decomposition to non-extractable 64Cu complexes were found in rat and human blood in vitro (70% ± 6% and 43% ± 5% respectively at 16 min), demonstrating the need for immediate processing of arterial samples. Close agreement was found between blood flow estimated by 64Cu-PTSM and 57Co microsphere methods in tissues of low to moderate flow: muscle (0.01, 0.08, 0.07 ml/min per gram; mean difference, mean 64Cu, mean 57Co), brain (0.09, 0.52, 0.43 ml/min per gram) and kidney (-0.16, 2.29, 2.45 ml/min per gram). Estimates of cardiac output also compared favourably between the two methods (5.7, 59.8, 54.1 ml/min). (orig./MG)

  5. Measures to decrease the risk of acquired immunodeficiency syndrome transmission by blood transfusion. Evidence of volunteer blood donor cooperation.

    Science.gov (United States)

    Pindyck, J; Waldman, A; Zang, E; Oleszko, W; Lowy, M; Bianco, C

    1985-01-01

    We studied whether volunteers giving blood to the Greater New York Blood Program (GNYBP) cooperated with procedures implementing public health recommendations intended to decrease the risk of acquired immunodeficiency syndrome (AIDS) transmission by blood transfusion. Predonation medical screening was expanded to exclude donors who might be ill with AIDS. To exclude possible asymptomatic carriers of the disease, members of groups at increased risk of AIDS were asked either not to give blood or to give it for laboratory studies. A confidential questionnaire, administered to all donors after medical screening, provided the vehicle for donors to advise the GNYBP whether their donation was for laboratory studies or for patient transfusion. We found that the number of male donors decreased; AIDS-related questions in medical history led to a 2 percent increase in donor rejections; 97 percent of donors said their blood could be used for transfusions; 1.4 percent said their blood could be used for laboratory studies only; and 1.6 percent did not respond. Only units designated for transfusion were released to hospitals. People who indicated that their donation was for laboratory studies had a higher prevalence of markers for hepatitis B virus and of antibodies to cytomegalovirus. White cell counts and helper/suppressor T lymphocyte ratios were not significantly different in the two groups. We conclude that volunteer donors have cooperated with the established procedures. None of the laboratory assays identified blood units donated by individuals who, based on information about AIDS high-risk groups, designated their donation for laboratory studies. PMID:3969698

  6. Timing of Peripheral Blood Stem Cell Yield: Comparison of Alternative Methods with the Classic Method for CD34+ Cell Determination

    Directory of Open Access Journals (Sweden)

    I. Fatorova

    2014-01-01

    Full Text Available Hematopoietic stem cells (HSCs, still represent a certain mystery in biology, have a unique property of dividing into equal cells and repopulating the hematopoietic tissue. This potential enables their use in transplantation treatments. The quality of the HSC grafts for transplantation is evaluated by flow cytometric determination of the CD34+ cells, which enables optimal timing of the first apheresis and the acquisition of maximal yield of the peripheral blood stem cells (PBSCs. To identify a more efficient method for evaluating CD34+ cells, we compared the following alternative methods with the reference method: hematopoietic progenitor cells (HPC enumeration (using the Sysmex XE-2100 analyser, detection of CD133+ cells, and quantification of aldehyde dehydrogenase activity in the PBSCs. 266 aphereses (84 patients were evaluated. In the preapheretic blood, the new methods produced data that were in agreement with the reference method. The ROC curves have shown that for the first-day apheresis target, the optimal predictive cut-off value was 0.032 cells/mL for the HPC method (sensitivity 73.4%, specificity 69.3%. HPC method exhibited a definite practical superiority as compared to other methods tested. HPC enumeration could serve as a supplementary method for the optimal timing of the first apheresis; it is simple, rapid, and cheap.

  7. Evaluation of MR angiography and blood flow measurement in abdominal and peripheral arterial occlusive disease

    Energy Technology Data Exchange (ETDEWEB)

    Tabuchi, Kenji [Dokkyo Univ. School of Medicine, Mibu, Tochigi (Japan)

    2000-03-01

    To assess the characteristics of blood flow measurement with MR Angiography (MRA) to evaluate the status of vascular stenoses, two or three dimensional time-of-flight MRA and velocity-encoded cine MR were performed in the 230 segments of 35 patients, with abdominal and peripheral arterial occlusive diseases. In 11 of these 35 patients digital subtraction angiography was additionally underwent, and the stenotic findings was compared with MRA. There were 17 segments in which the velocity could not be measured, because the blood flow exceeded the upper limit of peak-encoded velocity (VENC) which was set at 120 cm/sec. Therefore, it is necessary to set the upper limit of VENC at higher than 120 cm/sec. There were 11 stenotic findings in DSA and 20 stenotic findings in MRA. Pulsatility Index (PI=(max velocity-min. velocity)/average velocity) were used for evaluating the blood flow waveform, and there were significant difference between the 11 stenotic findings of DSA and the others'. In summery, MRA was considered as useful examination to assess the degree of the vascular stenoses in abdominal and peripheral arterial occlusive disease. (author)

  8. Rethinking traditional methods for measuring intellectual capital.

    Science.gov (United States)

    Corso, John A

    2007-01-01

    Historically, approaches to measuring intellectual capital have included both conventional accounting-based measures, such as variants of the market-to-book ratio, and more progressive measures, such as the measurement of intangible assets found in approaches such as the Balanced Scorecard and Human Resource Accounting. As greater emphasis is placed on intellectual capital and its various aspects in the continually growing service and knowledge economy, the use of assessment instruments to inventory the alignment, balance, and variety of intellectual capacities and metrics that assess the effectiveness of succession planning may represent new directions in which organizations can head in the measurement of this important construct. PMID:17198113

  9. Rethinking traditional methods for measuring intellectual capital.

    Science.gov (United States)

    Corso, John A

    2007-01-01

    Historically, approaches to measuring intellectual capital have included both conventional accounting-based measures, such as variants of the market-to-book ratio, and more progressive measures, such as the measurement of intangible assets found in approaches such as the Balanced Scorecard and Human Resource Accounting. As greater emphasis is placed on intellectual capital and its various aspects in the continually growing service and knowledge economy, the use of assessment instruments to inventory the alignment, balance, and variety of intellectual capacities and metrics that assess the effectiveness of succession planning may represent new directions in which organizations can head in the measurement of this important construct.

  10. Prenatal exposures to persistent organic pollutants as measured in cord blood and meconium from three localities of Zhejiang, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Gaofeng [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology Chinese Academy of Sciences, Wuhan, 430072 (China); State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Xu Ying [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology Chinese Academy of Sciences, Wuhan, 430072 (China)]. E-mail: xuying@ihb.ac.cn; Li Wen [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology Chinese Academy of Sciences, Wuhan, 430072 (China); Han Guanggen [Zhejiang Center for Disease Control and Prevention, Hangzhou, 310009 (China); Ling Bo [Chinese Center for Disease Control and Prevention, Beijing, 100050 (China)

    2007-05-15

    Prenatal exposures to persistent organic pollutants were assessed using the levels of PCBs and organochlorine pesticides (OCPs) measured in cord blood and meconium samples from Luqiao and two other localities of the Zhejiang province in China. Luqiao is a town with the largest site for disassembly of PCB-containing obsolete transformers and electrical waste in China. The other two localities Pingqiao (100 km NW of Luqiao) and Lin'an (500 km NW of Luqiao) are towns without known electronic or electrical waste sites. A total of 23 PCB congeners (including 12 dioxin-like) and 6 OCPs were measured using the traditional GC-{mu}ECD technique. Micro-EROD bioassay was additionally used to measure TCDD-based TEQ levels of the 12 dioxin-like PCBs. Significant correlations were found between the TEQs measured by the two methods, supporting the application of micro-EROD as a practical tool for complementing the chemical analysis. The data showed that {beta}-HCH, p,p'-DDE, and 6 PCB congeners (101, 138, 153, 180, 183, and 187) were the predominant pollutants, with PCB138 being the best indicator (predictor) for total PCB levels. Cord blood and meconium from Luqiao have higher levels of PCBs than those from the other two localities, suggesting that a disassembly site for electronic and electric waste would provide an environment for greater exposure to these chemicals. The cord blood or meconium levels of {beta}-HCH, though likewise considerably high, were comparable in the three localities. Similar findings were observed for p,p'-DDE. Pollution by these OCPs might have come from past use of agricultural pesticides in the three localities.

  11. Heat amount measuring method for radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Takakura, Masahide

    1998-10-09

    The present invention provides a device for easily and accurately measuring the amount of heat generated from high level radioactive wastes generated upon reprocessing of spent fuels. Namely, radioactive wastes are contained in a measuring vessel formed by using thick-walled iron plates. Air is circulated in the measuring vessel. The temperatures of charged air and discharged air are measured. Then the amount of heat dissipated from the radioactive wastes and the amount of heat dissipated from the iron plates due to absorption of {gamma}-rays to the iron plates are obtained based on the temperature difference. Accordingly, the amount of heat generated from the radioactive wastes can be measured accurately. In addition, there is provided an effect that the amount of heat generated from radioactive wastes can be measured by simple procedures of charging radioactive wastes in the measuring vessel and driving air circulation fans. (I.S.)

  12. Method of measuring thermal neutron characteristics

    International Nuclear Information System (INIS)

    The thermal neutron decay characteristics of an earth formation are measured by detecting indications of the thermal neutron concentration in the formation during first and second measurement intervals following irradiation of the formation with a burst of fast neutrons. These measurement intervals may be selected from a sequence of discrete time gates which begins following a predetermined time delay after the preceding neutron burst and extends over substantially the remainder of the interval between neutron bursts. The particular set of two measurement intervals used is selected from among a number of possible sets as a function of a previously measured value of the decay characteristic. Measurements of detected radiation, averaged over a plurality of first intervals following respective neutron bursts, and averaged over a greater plurality of second intervals, are used to provide a background-compensated measure of the average level of induced radiation. (author)

  13. Observational study comparing non-invasive blood pressure measurement at the arm and ankle during caesarean section.

    Science.gov (United States)

    Drake, M J P; Hill, J S

    2013-05-01

    Upper-arm non-invasive blood pressure measurement during caesarean section can be uncomfortable and unreliable because of movement artefact in the conscious parturient. We aimed to determine whether ankle blood pressure measurement could be used instead in this patient group by comparing concurrent arm and ankle blood pressure measured throughout elective caesarean section under regional anaesthesia in 64 term parturients. Bland-Altman analysis of mean difference (95% limits of agreement [range]) between the ankle and arm was 11.2 (-20.3 to +42.7 [-67 to +102]) mmHg for systolic arterial pressure, -0.5 (-21.0 to +19.9 [-44 to +91]) mmHg for mean arterial pressure and -3.8 (-25.3 to +17.8 [-41 to +94]) mmHg for diastolic arterial pressure. Although ankle blood pressure measurement is well tolerated and allows greater mobility of the arms than measurement from the arm, the degree of discrepancy between the two sites is unacceptable to allow routine use of ankle blood pressure measurement, especially for systolic arterial pressure. However, ankle blood pressure measurement may be a useful alternative in situations where arm blood pressure measurement is difficult or impossible. PMID:23480469

  14. Development of an aptamer-based concentration method for the detection of Trypanosoma cruzi in blood.

    Directory of Open Access Journals (Sweden)

    Rana Nagarkatti

    Full Text Available Trypanosoma cruzi, a blood-borne parasite, is the etiological agent of Chagas disease. T. cruzi trypomastigotes, the infectious life cycle stage, can be detected in blood of infected individuals using PCR-based methods. However, soon after a natural infection, or during the chronic phase of Chagas disease, the number of parasites in blood may be very low and thus difficult to detect by PCR. To facilitate PCR-based detection methods, a parasite concentration approach was explored. A whole cell SELEX strategy was utilized to develop serum stable RNA aptamers that bind to live T. cruzi trypomastigotes. These aptamers bound to the parasite with high affinities (8-25 nM range. The highest affinity aptamer, Apt68, also demonstrated high specificity as it did not interact with the insect stage epimastigotes of T. cruzi nor with other related trypanosomatid parasites, L. donovani and T. brucei, suggesting that the target of Apt68 was expressed only on T. cruzi trypomastigotes. Biotinylated Apt68, immobilized on a solid phase, was able to capture live parasites. These captured parasites were visible microscopically, as large motile aggregates, formed when the aptamer coated paramagnetic beads bound to the surface of the trypomastigotes. Additionally, Apt68 was also able to capture and aggregate trypomastigotes from several isolates of the two major genotypes of the parasite. Using a magnet, these parasite-bead aggregates could be purified from parasite-spiked whole blood samples, even at concentrations as low as 5 parasites in 15 ml of whole blood, as detected by a real-time PCR assay. Our results show that aptamers can be used as pathogen specific ligands to capture and facilitate PCR-based detection of T. cruzi in blood.

  15. Development of an Aptamer-Based Concentration Method for the Detection of Trypanosoma cruzi in Blood

    Science.gov (United States)

    Nagarkatti, Rana; Bist, Vaibhav; Sun, Sirena; Fortes de Araujo, Fernanda; Nakhasi, Hira L.; Debrabant, Alain

    2012-01-01

    Trypanosoma cruzi, a blood-borne parasite, is the etiological agent of Chagas disease. T. cruzi trypomastigotes, the infectious life cycle stage, can be detected in blood of infected individuals using PCR-based methods. However, soon after a natural infection, or during the chronic phase of Chagas disease, the number of parasites in blood may be very low and thus difficult to detect by PCR. To facilitate PCR-based detection methods, a parasite concentration approach was explored. A whole cell SELEX strategy was utilized to develop serum stable RNA aptamers that bind to live T. cruzi trypomastigotes. These aptamers bound to the parasite with high affinities (8–25 nM range). The highest affinity aptamer, Apt68, also demonstrated high specificity as it did not interact with the insect stage epimastigotes of T. cruzi nor with other related trypanosomatid parasites, L. donovani and T. brucei, suggesting that the target of Apt68 was expressed only on T. cruzi trypomastigotes. Biotinylated Apt68, immobilized on a solid phase, was able to capture live parasites. These captured parasites were visible microscopically, as large motile aggregates, formed when the aptamer coated paramagnetic beads bound to the surface of the trypomastigotes. Additionally, Apt68 was also able to capture and aggregate trypomastigotes from several isolates of the two major genotypes of the parasite. Using a magnet, these parasite-bead aggregates could be purified from parasite-spiked whole blood samples, even at concentrations as low as 5 parasites in 15 ml of whole blood, as detected by a real-time PCR assay. Our results show that aptamers can be used as pathogen specific ligands to capture and facilitate PCR-based detection of T. cruzi in blood. PMID:22927983

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

    Directory of Open Access Journals (Sweden)

    Jong-Gu Choi

    2011-01-01

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

  17. Measurement of utero-placental blood flow with /sup 113m/In in diabetic pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Semmler, K.; Kirsch, G.; Zoellner, P.; Fuhrmann, K.; Jutzi, E. (Zentralinstitut fuer Diabetes, Karlsburg (German Democratic Republic); Ernst-Moritz-Arndt-Universitaet, Greifswald (German Democratic Republic). Radiologische Klinik)

    1985-01-01

    In 122 diabetic pregnancies the placental blood flow has been estimated determining the half-life of the activity inflow (2 MBq /sup 113m/In-transferrin) into the placenta. A highly sensitive detector (modified pinhole collimator) and a computer-supported evaluation were used. 259 flow measurements were compared to the risk of complication in the course of diabetic pregnancy. The half-life values in the diabetic group, calculated by a gamma camera computer system by means of an iterative regression analysis, were significantly different compared to a control group (12 pregnancies without risk.) Severe diabetic angiopathic complications (classes D, F, and R according to White) are accompanied by higher half-life values (placental blood flow reductions) and perinatal complications. Even in pregnant women with gestational diabetes of disturbances of the carbohydrate metabolism disturbed placental hemodynamics is to be found.

  18. Simultaneous measurement of cerebral blood flow and oxygen extraction fraction by positron emission tomography: theoretical study and experimental evidence of cerebral blood flow measurement with the C15O2 continuous inhalation technique

    International Nuclear Information System (INIS)

    The method of the continuous inhalation technique of oxygen-15 labelled CO2 coupled with positron emission tomography for the measurement of cerebral blood flow (C.B.F.) is described. An indirect experimental verification that this technique allowed the measurement of C.B.F. has been carried out in baboons by showing the expected change in the measured parameter with variations in the PaCO2. A critical investigation of the C15O2 model was performed. The amount of tracer present in the cerebral vascular pool has a negligible effect on C.B.F. value. The use of a mean brain-blood partition coefficient of water instead of that specific to gray or to white matter is commented upon, and its influence on the final C.B.F. value is studied. Lastly, the problem of the limited diffusion of water across the blood-brain-barrier is discussed. The study of the combined effects of gray-white mixing and limited wates extraction of the C.B.F. value shows that the C15O2 technique tends to understimate real C.B.F., and that this error is more severe with high flows and even gray white mixing. These limitations do not depart from the possibility to estimate in the same brain locus not only C.B.F. but oxygen utilization as well by the consecutive inhalation of C15O2 and 15O2. The advantages of this possibility has already been shown in a number of clinical studies

  19. Noninvasive tracking of systolic arterial blood pressure using pulse transit time measured with ECG and carotid doppler signals with intermittent calibration

    OpenAIRE

    Fujita, Yoshihisa

    2016-01-01

    We have developed a non-invasive blood pressure measurement system using pulse transit time (PTT) from the heart to the common carotid artery, measured by using an electrocardiogram (ECG) R-wave and carotid arterial Doppler signals at the anterior neck. In this study, we examined the validity of our system by comparing PTT derived systolic blood pressure (Dopp_SBP) with invasive radial systolic arterial pressure (Inv_SBP) with calibration every 15 min in the ICU setting.Methods: 17 patients u...

  20. Non-invasive measurements of tissue hemodynamics with hybrid diffuse optical methods

    Science.gov (United States)

    Durduran, Turgut

    Diffuse optical techniques were used to measure hemodynamics of tissues non-invasively. Spectroscopy and tomography of the brain, muscle and implanted tumors were carried out in animal models and humans. Two qualitatively different methods, diffuse optical tomography and diffuse correlation tomography, were hybridized permitting simultaneous measurement of total hemoglobin concentration, blood oxygen saturation and blood flow. This combination of information was processed further to derive estimates of oxygen metabolism (e.g. CMRO 2) in tissue. The diffuse correlation measurements of blood flow were demonstrated in human tissues, for the first time, demonstrating continous, non-invasive imaging of oxygen metabolism in large tissue volumes several centimeters below the tissue surface. The bulk of these investigations focussed on cerebral hemodynamics. Extensive validation of this methodology was carried out in in vivo rat brain models. Three dimensional images of deep tissue hemodynamics in middle cerebral artery occlusion and cortical spreading depression (CSD) were obtained. CSD hemodynamics were found to depend strongly on partial pressure of carbon dioxide. The technique was then adapted for measurement of human brain. All optical spectroscopic measurements of CMRO2 during functional activation were obtained through intact human skull non-invasively. Finally, a high spatio-temporal resolution measurement of cerebral blood flow due to somatosensory cortex activation following electrical forepaw stimulation in rats was carried out with laser speckle flowmetry. New analysis methods were introduced for laser speckle flowmetry. In other organs, deep tissue hemodynamics were measured on human calf muscle during exercise and cuff-ischemia and were shown to have some clinical utility for peripheral vascular disease. In mice tumor models, the measured hemodynamics were shown to be predictive of photodynamic therapy efficacy, again suggesting promise of clinical utility