Analytical evaluation of i-STAT Portable Clinical Analyzer and use by nonlaboratory health-care professionals

1993 ◽  
Vol 39 (6) ◽  
pp. 1069-1074 ◽  
Author(s):  
E Jacobs ◽  
E Vadasdi ◽  
L Sarkozi ◽  
N Colman

Abstract We evaluated the performance of the i-STAT Portable Clinical Analyzer, a hand-held instrument that, with its current cartridge, analyzes for electrolytes, urea nitrogen, glucose, and hematocrit in approximately 60 microL of whole blood in approximately 90 s. Accuracy, imprecision, and linearity studies were performed with aqueous controls and standards and by split-sample analysis. Intrarun imprecision (CV) ranged from 0.34% to 3.97%. Total imprecision over a 2-month period ranged from 0.42% to 4.83%, with urea nitrogen and glucose analyses generating the higher values. Patients' results from the Portable Clinical Analyzer correlated well with those obtained for whole blood or plasma by the Nova Stat Profile 5, the Beckman Synchron CX3, or the Technicon H1 Hematology Analyzer, with Sylx values < 0.2 mmol/L for potassium; < 1.5 mmol/L for sodium, glucose, and urea nitrogen; < 2.4 mmol/L for chloride, and < 2.4% for hematocrit. We also ascertained imprecision and accuracy of the system placed in a cardiothoracic intensive-care unit and operated by nurses. There were no significant differences in either the imprecision or accuracy of the system in this setting. We conclude that operator technique is not a factor in the analytical performance of the system and that it can be used by nonlaboratorians with a high degree of confidence that reliable results will be obtained.

1997 ◽  
Vol 119 (1) ◽  
pp. 57-60
Author(s):  
S. Qin ◽  
G. E. O. Widera

When performing inservice inspection on a large volume of identical components, it becomes an almost impossible task to inspect all those in which defects may exist, even if their failure probabilities are known. As a result, an appropriate sample size needs to be determined when setting up an inspection program. In this paper, a probabilistic analysis method is employed to solve this problem. It is assumed that the characteristic data of components has a certain distribution which can be taken as known when the mean and standard deviations of serviceable and defective sets of components are estimated. The sample size can then be determined within an acceptable assigned error range. In this way, both false rejection and acceptance can be avoided with a high degree of confidence.


2018 ◽  
Vol 51 (4) ◽  
pp. 1050-1058 ◽  
Author(s):  
Fermin Otálora ◽  
A. Mazurier ◽  
J. M. Garcia-Ruiz ◽  
M. J. Van Kranendonk ◽  
E. Kotopoulou ◽  
...  

Crystallography has a long history of providing knowledge and methods for applications in other disciplines. The identification of minerals using X-ray diffraction is one of the most important contributions of crystallography to earth sciences. However, when the crystal itself has been dissolved, replaced or deeply modified during the geological history of the rocks, diffraction information is not available. Instead, the morphology of the crystal cast provides the only crystallographic information on the original mineral phase and the environment of crystal growth. This article reports an investigation of crystal pseudomorphs and crystal casts found in a carbonate-chert facies from the 3.48 Ga-old Dresser Formation (Pilbara Craton, Australia), considered to host some of the oldest remnants of life. A combination of X-ray microtomography, energy-dispersive X-ray spectroscopy and crystallographic methods has been used to reveal the original phases of these Archean pseudomorphs. It is found with a high degree of confidence that the original crystals forming in Archean times were hollow aragonite, the high-temperature polymorphs of calcium carbonate, rather than other possible alternatives such as gypsum (CaSO4·2H20) and nahcolite (NaHCO3). The methodology used is described in detail.


2003 ◽  
Vol 19 (01) ◽  
pp. 22-28
Author(s):  
John Craggs ◽  
Damien Bloor ◽  
Brian Tanner ◽  
Hamish Bullen

Internationally accepted compensation factors exist for the main commercial ship types, but as yet there are no reliable factors for some unusual ship types or naval vessels. There have been at least two attempts to develop factors for U.S. naval vessels, but at present there is no agreement regarding the validity of the proposed factors. The aim of this paper is to outline the methodology developed to determine compensated gross tonnage (CGT) factors for U.K. naval vessels. This ongoing area of work, instigated and funded by the U.K. Ministry of Defence (MoD) and carried out by First Marine International, has been undertaken in partnership with leading U.K. and European shipbuilders. Three different methods have been used to calculate factors for a Type 23 frigate and an auxiliary oiler replenishment vessel. There was a good correlation between the factors derived by each method, giving the researchers a high degree of confidence in the principal weight-based methodology. The derivation of naval CGT factors and the subsequent analysis will assist MoD to estimate construction budgets, improve acquisition strategies, and quickly assess the implications of changes on unit procurement costs. U.K. naval shipbuilders will benefit from the ability to benchmark themselves against other naval and commercial shipbuilders and assess opportunities for performance improvement. The paper also discusses disparities in productivity between naval and commercial shipbuilders. It puts forward the view that fundamental differences between the two sectors will mean naval shipbuilders will inherently exhibit a lower level of productivity than commercial yards of similar technology.


1985 ◽  
Vol 31 (5) ◽  
pp. 741-746 ◽  
Author(s):  
D G Deutsch ◽  
R J Bergert

Abstract We evaluated the Hewlett-Packard 5995B benchtop capillary gas chromatograph-mass spectrometer (GC-MS) for its ability to identify drugs commonly detected and (or) measured in the clinical toxicology laboratory. Initial experiments indicated that the instrument as originally configured, with an isolation valve between the gas chromatograph and mass spectrometer, was unsatisfactory for the identification of hypnotics-sedatives. However, with the capillary inserted directly into the ion source, we could detect 10 ng of these drugs on a total-ion chromatogram. The software programs cause the instrument to be highly automated. In terms of ease of operation and speed it was found suitable for use in a routine clinical laboratory. Chromatography of urine extracts on the capillary gas chromatograph-mass spectrometer yielded excellent resolution of parent compounds and metabolites (e.g., diphenhydramine together with approximately four metabolites and propoxyphene with four metabolites). However, the manufacturer's computer program used to evaluate the quality of the match between the experimental mass spectra and the 375 drug reference spectra was only moderately successful in identifying unknown compounds. The ability of this capillary GC-MS to identify most compounds with a high degree of confidence will be increased by enlarging the library to include more drugs and metabolites and by using a more reliable computerized matching program.


1977 ◽  
Author(s):  
J.A. Caprini ◽  
L. Zuckerman ◽  
E. Cohen ◽  
J.P. Vagher ◽  
V. Lipp

This report describes a new method for comparing overall clotting characteristics between normal individuals and those with proven malignancy using thrombelastographic (TEG) comparison of native and celite-activated specimens. Native whole blood TEG, celite-activated TEG, and standard coagulation tests were performed on the same blood collection in 90 normals and 90 patients with new malignancies and the results were used to derive a discriminate equation This equation classified correctly all 90 normals and 88 out of 90 cancer patients. The formulation was verified with an additional 82 patients with only one incorrect classification in the 31 cancer subjects. The standard coagulation tests did not discriminate without significant overlap between cancer patients and normals. The high degree of discrimination obtained with our TEG analysis provides a new tool to compare individual clotting differences that may have important clinical applications. However, the results cannot be extrapolated to selectively identify those with malignancy among the general population since many other stimuli may produce accelerated coagulability. This analysis does provide identification of accelerated coagulability in association with new malignancies.


CORROSION ◽  
10.5006/3559 ◽  
2020 ◽  
Vol 76 (8) ◽  
pp. 742-749
Author(s):  
Raul B. Rebak ◽  
Sheldon W. Dean

The sensitization of stainless steels may decrease their corrosion resistance in industrial applications. Traditional immersion tests exist to determine the degree of sensitization (DOS) of the stainless steels. However, electrochemical methods may be preferred because they are less expensive and faster to perform. The fast and robust double loop electrochemical potentiokinetic reactivation (DL-EPR) test has been introduced to the corrosion community some decades ago but an interlaboratory testing study was necessary to assess the repeatability and reproducibility of the DOS results. This work reports on a recent study where 11 laboratories returned results that show a high degree of confidence in the data obtained by DL-EPR.


2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
M. Kaliuzhna ◽  
J.-B. Van der Henst ◽  
V. Chambon

A critical human ability is to revise one's own beliefs in light of contradictory evidence. Many argue that it is precisely this ability that is missing among schizophrenic patients and that such a deficit could be the source of delusions. However, no study, as far as we know, has ever directly investigated belief revision ability in schizophrenia. Thus we introduced several tasks requiring patients to revise their beliefs. First, the Wason's hypothesis testing task (the 2-4-6 task) was used. Subjects have to discover a simple rule known by the experimenter concerning a series of three numbers. A belief revision deficit would suggest that patients are incapable of abandoning their initial hypothesis and finding such a rule, since this requires flexible evaluation and hypothesis testing. Second, the way patients treat advice was explored in a task involving encyclopaedic knowledge. According to the belief revision deficit theory, patients should exhibit no change in their answers when they encounter advice that differs from their own view; they should also have a high degree of confidence in their responses. Finally, a Myside bias task was used to see whether patients exhibit closed-mindedness concerning everyday topics. A belief revision deficit would predict that patients would show an important Myside bias, thus being incapable of envisaging arguments against their beliefs. Surprisingly, our findings suggest that deluded schizophrenics are in fact able to revise their beliefs in the light of evidence and alternatives. Further research is needed to establish the causes of delusions.


2017 ◽  
Vol 598 ◽  
pp. L7 ◽  
Author(s):  
P. Kervella ◽  
F. Thévenin ◽  
C. Lovis

Proxima and α Centauri AB have almost identical distances and proper motions with respect to the Sun. Although the probability of such similar parameters is, in principle, very low, the question as to whether they actually form a single gravitationally bound triple system has been open since the discovery of Proxima one century ago. Owing to HARPS high-precision absolute radial velocity measurements and the recent revision of the parameters of the α Cen pair, we show that Proxima and α Cen are gravitationally bound with a high degree of confidence. The orbital period of Proxima is ≈ 550 000 yr. With an eccentricity of 0.50+0.08-0.09, Proxima comes within 4.3+1.1-0.9 kau of α Cen at periastron, and is currently close to apastron (13.0+0.3-0.1 kau). This orbital motion may have influenced the formation or evolution of the recently discovered planet orbiting Proxima, as well as circumbinary planet formation around α Cen.


1999 ◽  
Vol 38 (03) ◽  
pp. 187-193 ◽  
Author(s):  
D. Hölzel ◽  
K. Überla ◽  
K. Adelhard

AbstractComputerized medical record systems have to present user-and problem-oriented views of a patient record to health-care professionals. Presentation and manipulation of data must be easily adaptable to current and future demands of medical specialties and specific settings. During the definition, development and evaluation of a prototype of a computerized patient record system, design elements were elaborated to support physicians and other health-care professionals. Our approach shows a high degree of flexibility and adaptability to specific needs, problem orientation and connectivity to other systems, via a hospital information network. The explicit description of the contents of a patient record allows to augment the number of items that can be recorded without modifying the data structure. New views on patient data can be added to the system without interfering with the routine use of the system. Application in several medical specialties proved the feasibility of our prototype.


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