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Comparison of automated and manual F-wave latency measurements.

OBJECTIVE: F-waves are well-established clinical neurophysiological studies. F-wave analysis is now cumbersome limiting the usefulness of F-waves. This study evaluates the accuracy and reliability of an automated analysis method for F-wave latencies. METHODS: F-waves following 20 supramaximal stimuli recorded from the extensor digitorum brevis muscle of 80 limbs (55 subjects) were analyzed. F-wave latencies were determined using a computer program developed by NEUROMetrix (Waltham, MA). These results were compared in a blinded fashion with manual measurements of the same datasets by a clinical neurophysiologist with established expertise in F-waves. The manual measurements were repeated once. RESULTS: The yield rate of automated median F-wave latencies was 100% with a correlation coefficient (CC) of 0.996 when compared with manual assignment results. For individual F-wave latency measurements, comparable values were 90% and 0.977, respectively. The repeated manual measurements revealed a yield rate and CC for median latencies of 100% and 0.998, respectively, with comparable values for individual latency measurements of 95% and 0.992. CONCLUSIONS: These results indicate the feasibility of a reliable computerized automated analysis of F-wave latencies. SIGNIFICANCE: A reliable automated analysis of F-waves should add meaningfully to the value of these responses in clinical neurophysiology.

Adult↗

Peripheral nerve morphometry: Comparison between manual and semi-automated methods in the analysis of a small nerve.

Manual nerve morphometry has been usually described as tedious, time consuming, difficult to perform correctly and subject to many sources of errors. The above considerations might suggest that fully automated image analysis systems could be ideally programmed to analyze myelinated fibers. However, operator intervention is necessary to manually eliminate dark tissue elements such as pericytes and Schwann cell nuclei. The aims of the present study were to compare the manual and semi-automated techniques in the evaluation of a small nerve, comparing the most commonly used morphometric parameters for nerve descriptions. The aortic depressor nerves (ADN) of male Wistar rats (N = 12) were prepared with conventional techniques for epoxy resin embedding. Manual morphometry was performed on photomicrographs using a digitizing tablet. Semi-automated morphometry was performed with the aid of computer software, on the same negative images used on the photographic procedure, which were scanned and digitized to a microcomputer. Our results show no differences between data obtained with both methods, for any of the evaluated parameters (area, perimeter, diameters, myelin sheath thickness, g ratio, distribution histograms). In conclusion, manual morphometry reproduced data obtained with semi-automated technique in a small nerve, with the advantages of being less-expensive and an affordable method.

Anatomy↗

Improvement and automation of artificial neural networks to estimate medical outcomes.

The lengthy process of manually optimizing a feedforward backpropagation artificial neural network (ANN) provided the incentive to develop an automated system that could fine-tune the network parameters without user supervision. A new stopping criterion was introduced--the logarithmic-sensitivity index--that manages a good balance between sensitivity and specificity of the output classification. The automated network automatically monitored the classification performance to determine when was the best time to stop training-after no improvement in the performance measure (either highest correct classification rate, lowest mean squared error or highest log-sensitivity index value) occurred in the subsequent 500 epochs. Experiments were performed on three medical databases: an adult intensive care unit, a neonatal intensive care unit and a coronary surgery patient database. The optimal network parameter settings found by the automated system were similar to those found manually. The results showed that the automated networks performed equally well or better than the manually optimized ANNs, and the best classification performance was achieved using the log-sensitivity index as a stopping criterion.

Cluster Analysis↗

Automated methods for multiplexed pathogen detection.

Detection of pathogenic microorganisms in environmental samples is a difficult process. Concentration of the organisms of interest also co-concentrates inhibitors of many end-point detection methods, notably, nucleic acid methods. In addition, sensitive, highly multiplexed pathogen detection continues to be problematic. The primary function of the BEADS (Biodetection Enabling Analyte Delivery System) platform is the automated concentration and purification of target analytes from interfering substances, often present in these samples, via a renewable surface column. In one version of BEADS, automated immunomagnetic separation (IMS) is used to separate cells from their samples. Captured cells are transferred to a flow-through thermal cycler where PCR, using labeled primers, is performed. PCR products are then detected by hybridization to a DNA suspension array. In another version of BEADS, cell lysis is performed, and community RNA is purified and directly labeled. Multiplexed detection is accomplished by direct hybridization of the RNA to a planar microarray. The integrated IMS/PCR version of BEADS can successfully purify and amplify 10 E. coli O157:H7 cells from river water samples. Multiplexed PCR assays for the simultaneous detection of E. coli O157:H7, Salmonella, and Shigella on bead suspension arrays was demonstrated for the detection of as few as 100 cells for each organism. Results for the RNA version of BEADS are also showing promising results. Automation yields highly purified RNA, suitable for multiplexed detection on microarrays, with microarray detection specificity equivalent to PCR. Both versions of the BEADS platform show great promise for automated pathogen detection from environmental samples. Highly multiplexed pathogen detection using PCR continues to be problematic, but may be required for trace detection in large volume samples. The RNA approach solves the issues of highly multiplexed PCR and provides "live vs. dead" capabilities. However, sensitivity of the method will need to be improved for RNA analysis to replace PCR.

Automation↗

An automated image-processing strategy to analyze dynamic arterial spin labeling perfusion studies. Application to human skeletal muscle under stress.

Arterial spin labeling (ASL) perfusion measurements allow the follow-up of muscle perfusion with high temporal resolution during a stress test. Automated image processing is proposed to estimate perfusion maps from ASL images. It is based on two successive analyses: at first, automated rejection of the image pairs between which a large displacement is detected is performed, followed by factor analysis of the dynamic data and cluster analysis to classify pixels with large signal variation characteristic of vessels. Then, after masking these "vascular" pixels, factor analysis and cluster analysis are further applied to separate the different muscles between low or high perfusion increase, yielding a functional map of the leg. Data from 10 subjects (five normal volunteers and five elite sportsmen) had been analyzed. Resulting time perfusion curves from a region of interest (ROI) in active muscles show a good accordance whether extracted with automated processing or with manual processing. This method of functional segmentation allows automated suppression of vessels and fast visualization of muscles with high, medium or low perfusion, without any a priori knowledge.

Adult↗

Anatomically constrained region deformation for the automated segmentation of the hippocampus and the amygdala: Method and validation on controls and patients with Alzheimer's disease.

We describe a new algorithm for the automated segmentation of the hippocampus (Hc) and the amygdala (Am) in clinical Magnetic Resonance Imaging (MRI) scans. Based on homotopically deforming regions, our iterative approach allows the simultaneous extraction of both structures, by means of dual competitive growth. One of the most original features of our approach is the deformation constraint based on prior knowledge of anatomical features that are automatically retrieved from the MRI data. The only manual intervention consists of the definition of a bounding box and positioning of two seeds; total execution time for the two structures is between 5 and 7 min including initialisation. The method is evaluated on 16 young healthy subjects and 8 patients with Alzheimer's disease (AD) for whom the atrophy ranged from limited to severe. Three aspects of the performances are characterised for validating the method: accuracy (automated vs. manual segmentations), reproducibility of the automated segmentation and reproducibility of the manual segmentation. For 16 young healthy subjects, accuracy is characterised by mean relative volume error/overlap/maximal boundary distance of 7%/84%/4.5 mm for Hc and 12%/81%/3.9 mm for Am; for 8 Alzheimer's disease patients, it is 9%/84%/6.5 mm for Hc and 15%/76%/4.5 mm for Am. We conclude that the performance of this new approach in data from healthy and diseased subjects in terms of segmentation quality, reproducibility and time efficiency compares favourably with that of previously published manual and automated segmentation methods. The proposed approach provides a new framework for further developments in quantitative analyses of the pathological hippocampus and amygdala in MRI scans.

Adult↗

Automation of NMR structure determination of proteins.

The automation of protein structure determination using NMR is coming of age. The tedious processes of resonance assignment, followed by assignment of NOE (nuclear Overhauser enhancement) interactions (now intertwined with structure calculation), assembly of input files for structure calculation, intermediate analyses of incorrect assignments and bad input data, and finally structure validation are all being automated with sophisticated software tools. The robustness of the different approaches continues to deal with problems of completeness and uniqueness; nevertheless, the future is very bright for automation of NMR structure generation to approach the levels found in X-ray crystallography. Currently, near completely automated structure determination is possible for small proteins, and the prospect for medium-sized and large proteins is good.

Automation↗

The future of automated red blood cell collection.

Automated red blood cell (RBC) collection is a newer but well-established form of donor apheresis. The technologies comprising and supporting apheresis have undergone significant advancements through the past 50 years, and we anticipate further improvements in devices and systems for automated RBC collection. Multiple factors must be considered in implementing automated RBC collections, but these procedures provide a way to draw additional RBC products that meet cGMP, regulatory, blood collector economic and donor objectives while maintaining or improving RBC availability. The continuing need for RBCs, accompanied by shrinking donor availability, would indicate that automated RBC collections will grow.

Automation↗

Total laboratory automation in Japan. Past, present, and the future.

The history of systematized automation in clinical laboratories in Japan started in 1981. At that time, about 12 laboratory technicians worked in a typical private University hospital laboratory (average size 1000 beds), whereas in national university hospitals (typical size 600 beds), the number of technicians was as low as 18-25. In 1981, the Kochi Medical School was founded as a new national school, and laboratory staffing was limited by the Ministry of Education to only 19 technicians for the first 3 years. Therefore, we started to develop a fully automated laboratory system by ourselves rather than accepting an intolerable shortage of technicians. The system was based on conveyor and robotic technology, and we called this approach systematization. Ten years later, systematized automation was introduced into the Japanese market. As a result, 72% of the national university hospitals in Japan installed commercial systems for systematization. There is a trend now in hospitals with sufficient numbers of technicians, to introduce fully automated systems in their laboratories as well, and even small hospitals with less than 100 beds are planning to introduce such systems. However, current technology is too expensive and not sufficiently standardized to meet the needs of these market segments in Japan. We recommend that companies agree on common shapes and sizes of racks and include more flexible robotic technology in their sample handling systems, to allow for plug and play systems and to make systematization affordable for every laboratory in the world.

Automation↗

An automated measuring system for fundus perimetry.

PURPOSE: In order to automate fundus perimetry, which is usually laborious because of the many manual operations and the frequent eye movements, we developed a new fundus perimeter with an automated measuring system using computer technology. METHODS: This fundus perimeter consists of an infrared fundus camera, a fundus-pursuit unit, and a target-display unit. Both units are personal computers operating on Windows. After presetting the measuring points on the fundus, perimetry is automatically performed. The fundus-pursuit unit recognizes and pursues the fundus reference region while calculating its coordinates in real time during perimetry. The target-display unit corrects the stimulus coordinates with data from the fundus-pursuit unit and even if eye movement occurs, automatically displays the stimulus targets at the correct retinal point that had been preset. RESULTS: Fundus perimetry can be automatically and precisely performed with this automated measuring system. It shortens the duration of the examination and frees the operator from the lengthy and laborious manual operations during perimetry. CONCLUSIONS: This automated measuring system will make fundus perimetry easier for the operator, as well as more popular for clinical use.

Adult↗

Fast and accurate automated measurements in digitized stereophotogrammetric radiographs.

Until recently, Roentgen Stereophotogrammetric Analysis (RSA) required the manual definition of all markers using a high-resolution measurement table. To automate this tedious and time-consuming process and to eliminate observer variabilities, an analytical software package has been developed and validated for the detection, identification, and matching of markers in RSA radiographs. The digital analysis procedure consisted of the following steps: (1) the detection of markers using a variant of the Hough circle-finder technique; (2) the identification and labeling of the detected markers; (3) the reconstruction of the three-dimensional position of the bone markers and the prosthetic markers; and (4) the computation of micromotion. To assess the influence of film digitization, the measurements obtained from nine phantom radiographs using two different film scanners were compared with the results obtained by manual processing. All markers in the phantom radiographs were automatically detected and correctly labeled. The best results were obtained with a Vidar VXR-12 CCD scanner, for which the measurement errors were comparable to the errors associated with the manual approach. To assess the in vivo reproducibility, 30 patient radiographs were analyzed twice with the manual as well as with the automated procedure. Approximately, 85% of all calibration markers and bone markers were automatically detected and correctly matched. The calibration errors and the rigid-body errors show that the accuracy of the automated procedure is comparable to the accuracy of the manual procedure. The rigid-body errors had comparable mean values for both techniques: 0.05 mm for the tibia and 0.06 mm for the prosthesis. The reproducibility of the automated procedure showed to be slightly better than that of the manual procedure. The maximum errors in the computed translation and rotation of the tibial component were 0.11 mm and 0.24, compared to 0.13 mm and 0.27 for the manual RSA procedure. The total processing time is less than 10 min per radiograph, including interactive corrections, compared to approximately 1 h for the manual approach. In conclusion, a new and widely applicable, computer-assisted technique has become available to detect, identify, and match markers in RSA radiographs and to assess the micromotion of endoprostheses. This new technique will be used in our clinic for our hip, knee, and elbow studies.

Automation↗

An automated new technique for scoring the rodent micronucleus assay: computerized image analysis of acridine orange supravitally stained peripheral blood cells.

We developed an automated image analysis system to obtain objective data for the rodent peripheral blood micronucleus assay with acridine orange (AO) supravital staining. The system was able to identify micronucleated reticulocytes (MNRETs) and to evaluate inhibition of bone marrow cell proliferation by measuring the reticular area of reticulocytes (RETs). We also developed automated equipment to produce homogeneous acridine orange-coated glass slides. This study was designed to compare automated scoring with manual scoring using 4 model clastogens and 2 mouse strains. The MNRET incidence induced by each clastogen was similar for automated and manual scoring, and there was good correlation (r=0.92) between the methods. In addition, an index of bone marrow toxicity based on the reticular area of RETs was compared to the conventional index (% of polychromatic erythrocytes (PCE) to total erythrocytes; PCE ratio) and was similar. The results indicated that our technique for computer-assisted image analysis for the micronucleus assay with AO supravitally stained peripheral blood RETs was comparable to conventional microscopic scoring, and it was superior in objectivity and statistical power.

Acridine Orange↗

Automation of Salmonella typhi phage typing.

Two steps in the procedure for bacteriophage typing of Salmonella typhi have been automated. The culture inoculum was applied by flooding the surface of phage agar in a 150x20 mm petri dish and removing the excess liquid with a safety pipettor. This step replaced the older method of manually preparing up to 100 individual areas for inoculation. The number of bacteria per unit area was the same with both methods, so the automated method involved no change in the technique. The second automated step involved use of a bacteriophage applicator which simultaneously dispensed 59 uniform drops of bacteriophages onto the inoculated plate. The automated procedure has reduced personnel time by about 90% with no less in sensitivity or accuracy.

Automation↗

Automated variable contrast acuity testing.

The results of clinical trials with a simple system for automating visual acuity measurements are presented. An inexpensive microcomputer: (1) presents acuity targets on a television screen, (2) uses patients' responses entered through a remote response box to control a staircase testing procedure, and (3) prepares a printed record of a patient's mean visual acuity and its standard deviation. The automated method: (1) offers a stable measure of visual performance, (2) provides an immediate analysis of the statistical significance of changes measured in visual acuity from one office visit to the next, and (3) gives results that are in general agreement with conventional chart testing methods when high contrast targets are used on the television screen. In addition, when medium and low contrast targets are used, the automated method provides a variable contrast acuity profile (VCAP), which describes visual performance at contrast levels that are vital to a patient's performance in daily life but not examined in conventional chart testing. VCAPs are measured clinically, and it is shown that the extent that a patient's acuity declines with decreasing contrast cannot be predicted from the patient's high contrast acuity. Automated variable contrast acuity testing is found to provide a simple, reproducible, clinically practicable method of documenting and quantitating the extent of a patient's visual difficulties at medium and low contrasts.

Adolescent↗

A semi-automated, microplate version of the SOS Chromotest for the analysis of complex environmental extracts.

Environmental monitoring for genotoxicity requires that a large number of measurements be made across space and time. This requirement demands a rapid and efficient bioassay system. The SOS Chromotest is a rapid, efficient bacterial system for the detection of DNA damaging agents. Over 100 publications have described its use on a variety of samples. Relatively few studies have used the test to examine complex mixtures. Effective testing of complex samples poses a variety of problems. Although solutions have been proposed, few have validated the resulting protocol. In this work we present a semi-automated microplate version of the SOS Chromotest for the examination of complex mixtures. Experiments were conducted to determine the optimal cell concentration, exposure time, substrate conversion time and S9 enzyme concentration. The performance of the method was evaluated using 6 reference genotoxins and 3 complex mixtures. The complex mixtures examined are extracts of diesel particulate matter, urban dust and coal tar. The results obtained indicate that optimal responses often require fewer cells (approximately equal to 5-10 x 10(6) CFU/ml) and a longer exposure (3 h) than that recommended in the original protocol. Interfering effects of colored and turbid samples are removed using centrifugation and initial optical density readings taken 60 min after cell resuspension and lysis. The performance of the established protocol was evaluated using mitomycin C and benzo[a]pyrene results for 207 microplates and solvent control results for 293 microplates. The results indicate that the established method is accurate, sensitive and precise. Coefficient of variation on mean SOSIP values for mitomycin C and benzo[a]pyrene are < 5%. Solvent control data indicate that the standard threshold for determination of a positive response (induction factor > 1.5) is excessively conservative. All liquid transfers were automated using the Biomek automated laboratory workstation. Automation permits a throughput of up to 72 samples per day and maintains excellent precision and accuracy.

Automation↗

Evaluation of automated RT-PCR to accelerate the laboratory diagnosis of foot-and-mouth disease virus.

Automated fluorogenic (5' nuclease probe-based) reverse transcription polymerase chain reaction (RT-PCR) procedures were evaluated for the diagnosis of foot-and-mouth disease (FMD) using suspensions of vesicular epithelium, heparinised or clotted blood, milk and oesophageal-pharyngeal fluid ('probang') samples from the United Kingdom (UK) 2001 epidemic and on sera from animals experimentally infected with the outbreak serotype O FMD virus strain. A MagNA Pure LC was initially programmed to automate the nucleic acid extraction and RT procedures with the PCR amplification carried out manually by fluorogenic assay in a GeneAmp 5700 Sequence Detection System. This allowed 32 samples to be tested by one person in a typical working day or 64 samples by two people within 10-12 h. The PCR amplification was later automated and a protocol developed for one person to complete a single test incorporating 96 RT-PCR results within 2 working days or for two people to do the same thing in around 12 h. The RT-PCR results were directly compared with those obtained by the routine diagnostic tests of ELISA and virus isolation in cell culture. The results on blood, probang and milk samples were in broad agreement between the three procedures but specific RT-PCR protocols for such material have to be fully optimised as perhaps have the positive-negative acceptance criteria. However, the automated RT-PCR achieved definitive diagnostic results (positive or negative) on supernatant fluids from first passage inoculated cell cultures and its sensitivity was greater than ELISA on suspensions of vesicular epithelium (ES) and at least equivalent to that of virus isolation in cell culture. The combined tests of ELISA, virus isolation in cell culture and RT-PCR might, therefore, only be required for confirmation of a first outbreak of FMD in a previously FMD-free country. Should a prolonged outbreak subsequently occur, then either ELISA plus RT-PCR or else RT-PCR alone could be used as the laboratory diagnostic tool(s). Either approach would eliminate the requirement for sample passage in cell culture and considerably advance the issue of laboratory diagnostic test results.

Animals↗

Validation of automated spectrofluroimetry for measurement of regional organ perfusion using fluorescent microspheres.

The fluorescent microsphere (FM) method for determination of regional organ blood flow is labor intensive, requiring processing of 100 s to 1000 s of samples per organ. To save time and reduce handling errors, we developed an automated fluorescence analysis system by interfacing a commercially available spectrofluorimeter and sample delivery unit to a PC, operated by a Windows95(R)-based program, WINFAC. WINFAC allows versatile analysis setup and instrument control for fluorescent intensity acquisition at fixed wavelengths or by synchronous scanning. Data is presented on screen, in real-time, and stored in text format. Reference analyses are performed at specified intervals and the coefficient of variation is continuously updated to monitor instrument performance. The automated system was validated against radioactive microspheres (RM) for lung perfusion in a pig and sheep and evaluated for analysis reproducibility. Fluorescent and radioactive microspheres were delivered by simultaneous injection into a femoral vein. Lungs were excised, flushed, dried at total lung capacity, and cubed into approximately 2cm(3) pieces (n=833 and 1560, pig and sheep, respectively). Radioactive count rates were determined for each lung piece (corrected for decay, background and spillover). Fluorescent dyes were extracted in solvent and intensities were determined at fixed wavelengths, using the automated spectrofluorimeter (corrected for background and spillover). Multi-color reference solutions were measured every 50 samples to monitor instrument reproducibility. Blood flow estimates for each piece determined by RM and FM methods were highly correlated: R(2)=0.98+/-0.017, Slopes=1.00+/-0.007 and Intercepts=0.00+/-0.006 (mean+/-SD). The CV of repeat reference analyses was 0.71%+/-0.16, a 30% to 50% reduction relative to manual analysis. Automated spectrofluorimetry reduces measurement errors and is a reliable and time saving advancement. With this technology, use of FM to measure regional lung perfusion approaches the ease and accuracy of the RM method.

Animals↗

Automated edge-detection technique for measurement of brachial artery reactivity: a comparison of concordance with manual measurements.

Concerns have been raised about the reproducibility of brachial artery reactivity (BAR), because subjective decisions regarding the location of interfaces may influence the measurement of very small changes in lumen diameter. We studied 120 consecutive patients with BAR to address if an automated technique could be applied, and if experience influenced reproducibility between two observers, one experienced and one inexperienced. Digital cineloops were measured automatically, using software that measures the leading edge of the endothelium and tracks this in sequential frames and also manually, where a set of three point-to-point measurements were averaged. There was a high correlation between automated and manual techniques for both observers, although less variability was present with expert readers. The limits of agreement overall for interobserver concordance were 0.13 +/- 0.65 mm for the manual and 0.03 +/- 0.74 mm for the automated measurement. For intraobserver concordance, the limits of agreement were - 0.07 +/- 0.38 mm for observer 1 and - 0.16 +/- 0.55 mm for observer 2. We concluded that BAR measurements were highly concordant between observers, although more concordant using the automated method, and that experience does affect concordance. Care must be taken to ensure that the same segments are measured between observers and serially.

Automation↗