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At least 1,513 records · Page 84Linked to original sources
PubMed2001

Conscious and automatic uses of memory in chronic pain patients.

Memory deficits in chronic pain patients are frequently observed. The objective of this study was to explore memory performances of chronic pain patients by using the Process Dissociation Procedure developed by Jacoby (J. Mem. Lang. 30 (1991) 513). This procedure permits to separate the contribution of controlled processes from automatic processes operating within a memory task. The results show a significant decrease of controlled processes in chronic pain patients. Furthermore for both groups, automatic processes contribute in a similar extent to the memory performance. The estimates of controlled processes in the chronic pain patients are significantly related to the fear of pain and catastrophic beliefs. This is interpreted as a sign of interference between the attention consumed by pain experience (namely fear related to pain) and the attention to be allocated to the memory task.

Adult↗
PubMed1978

[Demonstration and semi-automatic assay of gelatin in serum].

We suggest a semi-automatic method for the determination of gelatin. The measured concentration of gelatin is not dependant for the amino-acid composition of that plasma substitute preparation. Plasmatic proteins are separated previously from gelatin by precipitation using trichloracetic acid (5 p. cent; vol/vol). Modified gelatin lower in molecular weight than proteins can be found in the supernatant. It is determined by Lowry method with an automatic continuous flow system. Standardization must be realized using gelatin's solution since the developped coloration intensity with proteins is stronger. At electrophoresis, gelatin migrates essentially towards beta-globulins. beta-globulins increased with the gelatin level in serum. Percentage of variation for beta globulins and other fractions must be determinated in function of the protein level before perfusion. So it is possible to study the percentage of variation of these electrophoretic fractions independantly of the altered protein level.

Autoanalysis↗
PubMed1981

A complete automatic procedure for the characterisation of irregular antibodies.

Computer equipment has been attached to a normal double channel AA. Is consists of a micro-computer, a printer, a mini-floppy disk system and an analog to digital conversion interface which is the link between the AA and the computer. This "assembly line" was designed with three aims in mind: 1) to complete the automation of the chain by means of computerized management of the sampling (and ultimately its identification); 2) to perform an automatic antibody screening and identification from the sampling to the editing of all possible solutions; 3) to insert this test into a larger computerized context which consists of an automatic management and selection of the test red blood cell panel.

Agglutinins↗
PubMed1992

Development of an automatic program for the stereological estimation of the volume weighted mean volume of cell nuclei.

A stereological method was recently developed for the estimation of the volume weighted mean volume of particles from 2D sections. Several authors successfully applied this manual method to paraffin sections of bladder cancers and malignant melanomas and found a good correlation between the mean nuclear volume and the histological grading and prognosis of these tumors. The implementation of this measuring method on an automatic image analyser, devoted to routine work in tumor pathology, is presented. The accuracy of the automatic measurement has been evaluated together with the first results obtained from human esophageal cancers.

Cell Nucleus↗
PubMed2000

Detection of fiducial gold markers for automatic on-line megavoltage position verification using a marker extraction kernel (MEK).

PURPOSE: In this study automatic detection of implanted gold markers in megavoltage portal images for on-line position verification was investigated. METHODS AND MATERIALS: A detection method for fiducial gold markers, consisting of a marker extraction kernel (MEK), was developed. The detection success rate was determined for different markers using this MEK. The localization accuracy was investigated by measuring distances between markers, which were fixed on a perspex template. In order to generate images comparable to images of patients with implanted markers, this template was placed on the skin of patients before the start of the treatment. Portal images were taken of lateral prostate fields at 18 MV within 1-2 monitor units (MU). RESULTS: The detection success rates for markers of 5 mm length and 1.2 and 1.4 mm diameter were 0.95 and 0.99 respectively when placed at the beam entry and 0.39 and 0.86 when placed at the beam exit. The localization accuracy appears to be better than 0.6 mm for all markers. CONCLUSION: Automatic marker detection with an acceptable accuracy at the start of a radiotherapy fraction is feasible. Further minimization of marker diameters may be achieved with the help of an a-Si flat panel imager and may increase the clinical acceptance of this technique.

Algorithms↗
PubMed1997

Automatic three-dimensional expansion of structures applied to determination of the clinical target volume in conformal radiotherapy.

PURPOSE: A method is provided for the automatic calculation of the Clinical Target Volume (CTV) by automatic three dimensional (3D) expansion of the Gross Tumor Volume (GTV), keeping a constant margin M in all directions and taking into account anatomic obstacles. METHODS AND MATERIALS: Our model uses a description of the GTV from contours (polygons) defined in a series of parallel slices obtained from Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). Each slice is considered sequentially, including those slices located apart from the GTV at a distance smaller than M. In the current slice a two-dimensional (2D) expansion is performed by transforming each vertex of the polygon into a circle with a radius equal to M, and each segment into a rectangle with a height equal to 2M. A cartesian millimetric grid is then "projected" onto the slice and a specific value is assigned at each point depending if the point is internal to the 2D expansion. The influence in the current slice of any slice located at a distance delta z smaller than M is taken into account by applying a 2D expansion using a margin [formula: see text]. Additional contours representative of various "barriers" stopping the expansion process can also be defined. RESULTS: The method has been applied to cylindrical and spherical structures and has proven to be successful, provided that the slice thickness is small enough. For usual slice thicknesses and margins, it gives a slight overestimation of the additional volume (around 5%) due to the choice that the calculated target volume would not be less than the expected volume. It has been shown that for a spherical volume, a 2D expansion performed slice by slice leads to a volume up to 80% smaller than that obtained by 3D expansion. CONCLUSIONS: This tool, which mimics the tumor cell spreading process, has been integrated in our treatment-planning software and used clinically for conformal radiotherapy of brain and prostatic tumors. It has been found to be extremely useful, not only saving time but also allowing a precise determination of the CTV which would be impossible to do manually.

Algorithms↗
PubMed1982

[Electroencephalographic findings during open heart surgery. Automatic analysis in relation to parameters of anesthesia and use in intraoperative monitoring of cerebral function].

It is generally agreed upon by experts that EEG monitoring of brain function during open heart surgery is of the utmost importance in preventing postoperative neurological and psychopathological consequences. Up to now, however, this monitoring has not been performed on a large scale: (1) it is a very time-consuming task for the clinical neurophysiologist: (2) the anesthetist does not generally possess enough knowledge of this part of neurophysiology to get more than only a rough impression of the alterations of brain function during these procedures. To improve this situation we developed an automatic method to monitor brain function: the results of period-amplitude analysis of the EEG are continuously related to a number of important parameters--blood pressure, temperature, anesthesia. The way this is done resembles to a large degree the procedure which the neurophysiologist uses to judge the EEG during monitoring. The system generates warning and alerting signals, which also indicate the kind of disturbance when a marginal situation occurs. The anesthetist may take measures within 1 min to restore the condition. This is in complete agreement with the needs of anesthesiology. By means of a special function keyboard the anesthetist uses the system interactively and introduces all the necessary information which is needed for the proper functioning of the warning system (kind and quantity of different anesthetics and other drugs). At the end of the procedure the total information about the EEG, patient parameters and anesthetic measures are plotted in graphical form and printed as a table for documentation purposes which to a large degree may do away with the usual documentation. The introduction of this automatic monitoring system opens the way to a large scale use of EEG monitoring during open heart surgery.

Anesthesia, General↗
PubMed1986

[Development of a criterion for the automatic detection of sleep spindles in the infant].

The authors present a model for automatic detection of spindles during the different sleep stages. Baseline spindle-free EEG was modelized on a 10 sec recording using an autoregressive model. Spindles were thereafter detected using the quadratic error from this baseline model on successive 1 sec periods. This automatic detection is in a 95.7% agreement with visual analysis.

Computers↗
PubMed2001

On-line, continuous and automatic monitoring of extracellular malondialdehyde concentration in anesthetized rat brain cortex.

An assay for in vivo, continuous and automatic monitoring of extracellular malondialdehyde concentrations in anesthetized rat brain cortex was developed. This method involved the use of microdialysis perfusion, on-line derivatization and on-line high-performance liquid chromatographic analysis. Microdialysate from an implanted microdialysis probe was on-line reacted with thiobarbituric acid at 80 degrees C for 10 min prior to on-line collection and automatic injection into a HPLC system equipped with a fluorescence detector. This method gave a linear response between the concentrations of the malondialdehyde in the microdialysates and the TEP solution where the microdialysis probe was placed. This method was used to observe the increased extracellular malondialdehyde production following elevated extracellular glutamate levels, which were achieved by perfusion of L-trans-pyrrolidine-2,4-dicarboxylate, a competitive inhibitor of glutamate uptake transporter.

Animals↗
PubMed2000

Semi-automatic liquid chromatographic analysis of olpadronate in urine and serum using derivatization with (9-fluorenylmethyl)chloroformate.

The semi-automatic bioanalytical assays for olpadronate [(3-dimethylamino-1-hydroxypropylidene)bisphosphonate] involves a protein precipitation with trichloroacetic acid and a double co-precipitation with calcium phosphate for serum samples and a triple calcium co-precipitation for urine samples. These manual procedures are followed by an automated solid-phase extraction on a cation-exchange phase. The procedure is continued either directly, at high olpadronate levels in urine, or after off-line evaporation under nitrogen and reconstitution in water on the same robotic workstation. The continued automatic procedure comprehends derivatization with (9-fluorenylmethyl)chloroformate, ion-pair liquid-liquid extraction and ion-pair HPLC with fluorescence detection at 274/307 nm. The intra- and inter-day precisions for urine and serum samples are typically in the 5-8% range for different olpadronate concentrations [levels near the lower limit of quantification (LLQ) excluded]. The LLQ is 5 ng/ml olpadronate for a 2.5-ml urine sample and 10 ng/ml for a 1-ml serum sample, respectively.

Automation↗
PubMed2000

Semi-automatic analysis of fire debris

Automated analysis of fire residues involves a strategy which deals with the wide variety of received criminalistic samples. Because of unknown concentration of accelerant in a sample and the wide range of flammable products, full attention from the analyst is required. Primary detection with a photoionisator resolves the first problem, determining the right method to use: the less responsive classical head-space determination or absorption on active charcoal tube, a better fitted method more adapted to low concentrations can thus be chosen. The latter method is suitable for automatic thermal desorption (ATD400), to avoid any risk of cross contamination. A PONA column (50 mx0.2 mm i.d.) allows the separation of volatile hydrocarbons from C(1) to C(15) and the update of a database. A specific second column is used for heavy hydrocarbons. Heavy products (C(13) to C(40)) were extracted from residues using a very small amount of pentane, concentrated to 1 ml at 50 degrees C and then placed on an automatic carousel. Comparison of flammables with referenced chromatograms provided expected identification, possibly using mass spectrometry. This analytical strategy belongs to the IRCGN quality program, resulting in analysis of 1500 samples per year by two technicians.

Journal Article↗
PubMed2000

Automatic measurement of changes in brain volume on consecutive 3D MR images by segmentation propagation.

This article presents a technique to automatically measure changes in the volume of a structure of interest in successive 3D magnetic resonance (MR) images and its application in the study of the brain and lateral cerebral ventricles. The only manual step is a segmentation of the structure of interest in the first image. The analysis comprises, first, precise rigid co-registration of the time series of images; second, computation of residual deformations between pairs of images; third, automatic quantification of the volume change, obtained by propagation of the segmentation of the structure of interest through the series of MR images. This approach has been applied to monitor changes in the volume of the brain and lateral cerebral ventricles in a healthy subject and a patient with primary progressive aphasia (PPA). Results are consistent with those obtained by application of the boundary shift integral (BSI) and by stereology in the same subjects.

Aged↗
PubMed2001

Automatic multicommmutated flow system for diffusion studies of pharmaceuticals through artificial enteric membrane.

An automatic flow procedure with spectrophotometric detection was developed for the study of pharmaceuticals diffusion through an artificial enteric membrane. The manifold comprised two independent flow pathways, gathered by a diffusion unit with two compartments and an enteric lipophilic membrane. The pathways were automatically filled with solutions simulating digestive and plasmatic conditions by means of four solenoid valves. The diffusion of pharmaceuticals from the enteric to the plasmatic compartment was performed in closed loop pathways, and was continuously monitored by a flow cell coupled to the acceptor solution pathway. The volumes of the digestive and plasmatic solutions were 6.0 and 3.6 ml, respectively, which comprised filling unit compartment, pumping tubing and connecting flow lines. Pumping flow rates of donor and acceptor solutions were maintained at 6.0 and 2.5 ml min(-1), respectively. The proposed system was employed in diffusion studies of caffeine and aminophylline, and in the evaluation of the influence of tensioactive agents on the diffusion process. After continuous solutions circulation for 60 min, caffeine concentration in the acceptor stream was ca. 18% of its initial concentration at the digestive compartment. The system could be programmed to perform several replicates, stopping them with different degrees of diffusion without operator assistance. The data generated by the spectrophotometer was read by the microcomputer as a time function, and stored for further mathematical treatment.

Aminophylline↗
PubMed1985

The automatic implantable cardioverter-defibrillator: an overview.

The automatic implantable cardioverter-defibrillator continuously monitors the heart, identifies malignant ventricular tachyarrhythmias and then delivers electrical countershock to restore normal rhythm. There are two defibrillating electrodes which are also used for waveform analysis; one is located in the superior vena cava and the other is placed over the cardiac apex. A third bipolar right ventricular electrode is used for rate counting and R wave synchronization. When ventricular fibrillation occurs, a 25 J pulse is delivered; when ventricular tachycardia faster than the preset rate is detected, the discharge is R wave-synchronized. The clinical evaluation study of this therapeutic method began in February 1980 in patients with recurrent refractory life-threatening ventricular tachyarrhythmias. So far, the device has been implanted in nearly 500 patients with a follow-up period of up to 59 months. The risks and complications associated with this treatment were found to be moderate. Actuarial analysis has demonstrated significant impact on the survival rate of the patients receiving implants with 1 year arrhythmic mortality rate reduced to 2% or less in all groups analyzed. The available data indicate that the automatic cardioverter-defibrillator can reliably identify and correct potentially lethal ventricular tachyarrhythmias, leading to a substantial improvement in survival in properly selected high risk patients.

Adolescent↗
PubMed1985

Out-of-hospital automatic cardioversion of ventricular tachycardia.

A 42 year old man who survived sudden cardiac death was treated with an automatic implantable cardioverter/defibrillator. After a 5 month symptom-free interval, the patient received two internal discharges in the conscious state while wearing an ambulatory electrocardiographic recorder. Analysis of the tape revealed that both discharges were activated by two bursts of polymorphous ventricular tachycardia, the first one occurring at the end and the second at the onset of episodes of slow, hemodynamically stable monomorphous ventricular tachycardia. This case illustrates the reliability of the automatic implantable cardioverter/defibrillator as an antiventricular tachycardia device and the problem posed by its exposure to nonsustained ventricular tachycardia.

Adult↗
PubMed1985

Automaticity of the Kent bundle: confirmation by phase 3 and phase 4 block.

Automaticity in the Kent anomalous atrioventricular bundle has been postulated to occur on the basis of electrocardiographic recordings. This hypothesis was confirmed using intracardiac recordings and programmed stimulation in a patient with pre-excitation. It was supported, in part, by demonstrating the presence of phase 3 and phase 4 block in the Kent bundle during decremental atrial pacing. The existence of automaticity in the Kent bundle may explain the manifestation of intermittent pre-excitation in certain patients. Furthermore, the presence of phase 3 and phase 4 block makes the likelihood of rapid antidromic conduction over the Kent bundle pathway unlikely within this subgroup.

Atrial Fibrillation↗
PubMed1985

Transvenous catheter ablation of a right atrial automatic ectopic tachycardia.

A 10 year old patient with right atrial automatic ectopic tachycardia underwent successful transvenous catheter ablation after endocardial mapping. Tachycardia had been present for 7 years before ablation and associated with development of dilated cardiomyopathy. A single 50 J discharge at the point of earliest atrial activation was followed by the establishment of sinus rhythm that remains at 10 months' follow-up. This case represents the first reported successful catheter ablation of an atrial automatic ectopic tachycardia. Specific anatomic factors favoring successful ablation and improvement in technique are discussed.

Cardiac Catheterization↗
PubMed1987

Automatic external defibrillators: importance of field testing to evaluate performance.

A new automatic external defibrillator was tested first against a tape-recorded data base of rhythms and then during use by first-responding fire fighters in a tiered emergency system. The sensitivity for correctly classifying ventricular fibrillation and ventricular tachycardia was substantially less during clinical testing in 298 patients than would have been predicted from preclinical results: 52% of ventricular fibrillation analyses in patients were correctly classified versus 88% of episodes in the data base, and 22 versus 86%, respectively, for ventricular tachycardia (p less than 0.001). The detection algorithm was modified and evaluated further in another 322 patients. The modified detector performed substantially better than did the one that had been designed from prerecorded rhythms: with its use, 118 (94%) of 125 patients in ventricular fibrillation were counter-shocked compared with 91 (77%) of 118 similar patients with use of the initial algorithm (p less than 0.001). No inappropriate shocks were delivered. This improvement resulted in a shorter time to first shock (p less than 0.01) and more shocks being delivered for persistent or recurrent episodes of ventricular fibrillation (p less than 0.05). Of 620 patients treated with the automatic defibrillator, 243 (39%) had ventricular fibrillation; 57 (23%) of the 243 regained pulse and blood pressure before paramedics arrived, 141 (58%) were admitted to hospital and 71 (29%) were discharged.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗