Tool For Routine Monitoring Research Articles

Routine utilization of the transient hyperaemic response test after aneurysmal subarachnoid haemorrhage.

In order to explore the applicability of daily cerebral autoregulation monitoring through routine utilization of the transient hyperaemic response (THR) test in patients after aneurysmal subarachnoid haemorrhage (SAH), we performed THR tests daily in 50 consecutive patients with verified SAH. Out of 1167 studies, the test results were acceptable during 954 procedures (81.5%). 310 negative (32.5%; range 0.75-1.099; mean 1.03) and 644 positive (67.5%; range 1.10-1.77; mean 1.19) test results were obtained. Multiple logistic regression analysis revealed that the registration of negative THR in a middle cerebral artery (MCA) during the period of critical care was related to the patients' poor clinical grade (p-0.02) and Fisher CT-grade (p-0.04) on admission, to the development of vasospasm (p-0.003) and to the detection of ipsilateral intracerebral haemorrhage and/or cerebral infarction (p-0.01). The frequent registration of negative THR tests (negative results in > 30% of all the tests in an MCA) was independently related to the detection of ipsilateral intracerebral haemorrhage and/or cerebral infarction (p-0.0001). THR tests provide information about intracranial alterations and can be safely performed as a routine monitoring tool after SAH.

Less invasive, continuous hemodynamic monitoring during minimally invasive coronary surgery

Background. Minimally invasive coronary surgery has gained more and more clinical acceptance. A clear contrast to the minimally invasive idea is the highly invasive pulmonary artery catheter used for hemodynamic monitoring during the operation. We evaluated a less invasive device which calculates cardiac output (CO) and hemodynamics based on arterial pulse-contour analysis. Methods. In 20 patients revascularized by the off-pump technique with the octopus system, agreement of CO by pulse-contour was compared to pulmonary arterial and femoral arterial thermodilution and hemodynamic alterations during the operation were recorded. Pulse-contour CO is computed by measuring the area under the arterial pressure waveform and dividing it by aortic impedance. Aortic impedance is determined by an arterial thermodilution at the onset of the system. Results. Correlation of pulmonary arterial and arterial thermodilution CO to pulse-contour CO was 0.91 and 0.90 respectively (both p < 0.01). Coefficients of variations were 6.2% and 6.7%. The bias was 0.1 L per minute and standard deviations were 0.42 L per minute and 0.55 L per minute. Hemodynamic changes during the operations were seen mainly during the distal anastomosis of the first diagonal branch; only slight changes occurred during the anastomosis of the left anterior descending coronary artery. Conclusions. Arterial pulse-contour analysis is easy to use and minimally invasive, thus qualifies as a reliable routine monitoring tool during minimally invasive coronary surgery with tissue stabilizers.

Study on air pollution monitoring in Korea using low volume air sampler by instrumental neutron activation analysis

The aim of this research was to enhance the use of nuclear analytical techniques for air pollution studies and to study the feasibility of the use of instrumental neutron activation analysis (INAA) as a routine monitoring tool to reveal environmental pollution sources. For the collection of air particulate samples, the Gent stacked filter unit, low volume sampler with Nucleopore membrane filters were used. Trace elements in samples collected at two suburban residential sites, Taejon and Wonju city in the Republic of Korea, were analyzed by INAA. Variations of the elemental concentrations were measured monthly and the enrichment factors were calculated for the fine (<2 μm EAD) and coarse size (2–10 μm EAD) fractions. The analytical data were treated statistically to estimate the relationship between the two variables, the concentrations of elements and the total suspended particulate matter. The results were used to describe the emission source and their correlation.

Capillary electrophoresis as a routine industrial tool for quantitative analytical testing Determination of sodium dimethyldithiocarbamate in effluents

The determination of specific anionic species (sodium dimethyldithiocarbamate) in waste water was performed by capillary electrophoresis with direct UV detection. The application of new technology sulfonic acid polymer-coated capillary columns achieved sensitive analysis with robust electroosmotic flow (EOF), where other coated columns and conventional fused-silica had failed due to analyte adsorption problems. Optimum conditions for the separation of cationic, neutral, and other anionic species, including quantitative analyses of the analyte of interest, were obtained. The relative standard deviations for the analysis of anions were found to be 2.7 and 12.8% for 528 and 37 μg/ml concentrations, respectively. The detcction limit for sodium dimethyldithiocarbamate in waste water was established at 1 μg/ml for typical sample size (2 ml) without preconcentration of the analyte. The usefulness of capillary electrophoresis as a routine industrial monitoring tool was successfully demonstrated.

Study on air pollution monitoring in Korea using instrumental neutron activation analysis

Trace elements in airborne particulate matter collected monthly at suburban and rural areas in Korea were analyzed by instrumental neutron activation analysis (INAA). Neutron irradiation of the samples was done at the irradiation hole (neutron flux 1·1013 n·cm−2·s−1) of the TRIGA Mark-III Research Reactor in the Korea Atomic Energy Research Institute. For the verification of the analytical technique, two reference materials, NIST SRM-1648 and NIES CRM-8, were chosen for analysis. The accuracy and precision of the determinations of the 40 elements were compared with the reference values. We used this method (1) to analyze 30 trace elements in airborne particulate matter collected monthly with the high volume air sampler (PM-10) at two different locations and (2) to confirm the possibility of using this method as a routine monitoring tool to find out environmental pollution sources.

Ocean Surface Wave Measurement Using a Steerable High-Frequency Narrow-Beam Ground Wave Radar

Ground wave radar is emerging as an important tool for routine monitoring of ocean surface conditions and for ship and sea-ice surveillance at ranges well beyond the line-of-sight horizon that limits conventional systems. A major Canadian advance in this field is the recent development of a long-range ground wave radar facility at Cape Race, Newfoundland. Owned and operated by the Northern Radar Systems Limited, this short-based radar system can monitor ocean surface conditions over a 120° sector out to a range of 200 km for sea state and to a range of 300 km for ocean surface currents. The near-real-time surface wave parameters are extracted from the Doppler spectra of the frequency-modulated interrupted continuous wave ground wave radar system. This paper presents a brief overview of the radar system and discusses the process of extracting the one-dimensional wave spectrum and significant wave height from the Doppler spectra. The latter involves both the direct inversion of the HF (high frequency) radar cross section of the ocean surface as well as the least square fitting of modeled UF spectra. The ground wave radar facility at Cape Race was used in the measurement of wave parameters during the SAR (synthetic aperture radar) wave spectra validation experiments, offshore Newfoundland during November 1991. The SAR is one of the sensors aboard the European Space Agency's Remote Sensing Satellite (ERS-1) launched in June 1991. The wave parameters deduced by the ground wave radar were evaluated against buoy measurements as well as against hindcast values from the operational wave model, Canadian Spectral Ocean Wave Model. The radar-deduced wave heights were also evaluated against wave height charts prepared routinely by the Meteorology and Oceanography Centre at Halifax, Nova Scotia. Overall, a very good agreement was obtained. The utility of the radar for nearshore wave analysis and nowcasting, as well as for offshore surveillance, is discussed.

Innovations in Intra-Aortic Balloon Pump Management: Computer Modem Technology

The computer modem technology being developed by Datascope Corporation for the purpose of off-site intra-aortic balloon pump (IABP) monitoring was clinically evaluated in 30 patients requiring IABP support. The Datascope System 95 model IABP with built-in modem was used on all patients. Remote communications via a personal computer with modem were conducted under both routine and emergency settings. The Datascope PC IABP software was evaluated for its user compatibility, efficiency, diagnostic capability and overall usefulness as a clinical tool. During the eight month evaluation period, 87 remote communications were conducted for both routine and emergency IABP evaluation checks. Adjustments were recommended on 22 occasions relevant to balloon timing, trigger mode selection and augmentation volume settings. Eight communications were initiated in emergency settings due to a variety of patient conditions. Emergency intervention was successful in diagnosing and resolving critical situations including atrial arrhythmias, pacemaker timing, low cardiac output syndrome, loss of trigger source, catheter malpositioning and poor augmentation. The diagnostic capabilities and efficient means of data collection by the computer software provide the clinician with a valuable tool for routine IABP clinical monitoring, as well as emergency problem resolution.

Static headspace gas chromatographic determination of fault gases dissolved in transformer insulating oils

The analysis of dissolved gases in power transformer oils is an efficient diagnostic tool for routine performance monitoring of power transformers. A static headspace gas chromatographic method has been developed to automate the analysis. The parametric study showed that initial equilibration time is about 200 min at 70°C and set the sample volume to 15 ml of oil. Distribution coefficient values were determined under these optimized headspace conditions, avoiding the need of subsequent calibration from oil standards. The precision of the method was better than 5% and detection limits for hydrogen, carbon monoxide and methane, carbon dioxide, and hydrocarbons were 7, 10, 5 and 1 ppm (v/v), respectively. The response is linear over 3 decades up to 1000 ppm. A comparison study between the headspace and the currently used ASTM D3612 method using on-line transformer oil samples showed a good agreement. The headspace method permits an increased number of analysis per day, as much as four times, compared to the ASTM method.

The Liverpool Congenital Malformations Registry.

Data collection and validation for the Liverpool Congenital Malformations Registry (LCMR) are described. Founded in 1960, the LCMR increased its area of surveillance in 1979 to include five health districts in Liverpool and its environs with approximately 20,000 births per annum. The LCMR is now one of the members of the European Congenital Anomalies Register (EUROCAT). Multiple sources of ascertainment are employed, the most useful of these being OPCS notifications, hospital discharge letters and data from specialised paediatric units. In spite of several difficulties encountered in data collection the data base is an invaluable tool both for routine monitoring of prevalence rates and as a starting point for epidemiological research.

MST radar studies of wind and turbulence in the middle atmosphere

A survey is presented of recent developments in the observation of wind and turbulence in the stratosphere and mesosphere using MST radars. One of the highlights of these developments is the growing recognition that the MST/ST radar is a valuable tool for routine monitoring of the atmospheric wind field. Furthermore, preliminary observations have shown the feasibility of monitoring atmospheric turbulence as well. Recent observations of mesospheric turbulence support theoretical models that emphasize the role of propagating waves in coupling the lower and middle atmospheres. Scientific groups in several countries are now planning or constructing MST radars so that within a few years observations should be available from diverse geographical locations spanning the globe.

Sonomicrometry: Its Application as a Routine Monitoring Technique in Cardiac Surgery

We utilized ultrasonic-dimension crystals in approximately 50 patients during a three-year period to evaluate clinical sonomicrometry as a routine monitoring tool in patients undergoing cardiac operations. Standard research piezoelectric pulse transit ultrasonic transducers were modified with a hooked attachment in a tethered configuration to facilitate accurate alignment and quick insertion for the measurement of myocardial segment length changes. These segment crystals were used both intra-operatively and postoperatively to evaluate the left ventricular pressure–geometry relationships and to serve as a continuous monitor of myocardial function. The left ventricular pressure–volume relationship was varied by temporarily reapproximating the pericardium (pericardial closure resulted in a 12% reduction in fractional shortening, a 5% decrease in end-diastolic segment length, and an 8% increase in pulmonary artery diastolic pressure). During both the intraoperative and postoperative periods, we found good correlation between thermodilution, stroke volume, and myocardial dimensions; no correlation was noted between pulmonary artery diastolic pressure and stroke volume. No bleeding or major complications resulted from the use of these sonomicrometry transducers. Our initial clinical experience with sonomicrometry seems to support its use as a potentially valuable monitoring tool.

Quantification of Glucose, Fructose and Sucrose in Apple Juices Using ATR-MIR Spectroscopy Coupled with Chemometry

A combination of Fourier transform infrared spectroscopy (FTIR) and multivariate statistics (chemometry) was applied as a screening tool for the quantitative determination of carbohydrates, such as glucose, fructose and sucrose, in 11 processed commercial apple juices and 2 genuine juices obtained from squeezed apples. For calibration, a number of 24 mixtures of glucose, fructose and sucrose solutions (synthetic samples), at different concentrations were prepared and scanned in the 885 and 1500 cm-1 spectral range, using attenuated total reflectance (ATR) FTIR spectroscopy. Based on the mixtures spectra in the mid IR (MIR) region, we realized calibration models for each carbohydrate, using partial least squares (PLS) regression. The models were then used to predict the glucose, fructose and sucrose concentration in commercial apple juices, comparatively with concentrations in fresh, genuine juices, in order to assess the juice authenticity. The glucose concentrations (%, w/w) predicted for commercial juices ranged from 1.664 to 3.133 versus 3.1 for genuine fresh juices. The fructose concentrations (%, w/w) predicted for commercial juices ranged from 3.701 to 6.941 versus 9.2 for genuine fresh juices, while the sucrose concentrations (%, w/w) predicted for commercial juices ranged from 0.746 to 5.795 versus 1.38 for genuine fresh juices. The standard deviations of most predicted values are below 10%. Most juices exhibited glucose, fructose and sucrose concentrations in the expected range. However, several samples showed discrepancies from average concentration values, thus the authenticity of these juices could not be confirmed. Also, high sucrose concentration can flag adulterated juices, or indicates sucrose addition to maintain the juice sweetness intensity. Our results indicate ATR-MIR spectroscopy to be a rapid, accurate, non-destructive and cost-effective tool for routine monitoring of multiple constituents in apple juices, as quality and safety indicators.