Fast Scanning Mode Research Articles

Enhanced scanning control in a confocal scanning laser microscope

AbstractA fast and flexible scanning unit, allowing scanning rates of more than 1 kHz over regions identified in a specimen, has been developed and evaluated. This scanning unit replaces the original scanning unit in the Phoibos confocal scanning laser microscope and features full backward compatibility, while at the same time allowing fast and flexible scanning modes, such as point scanning, line scanning, and scanning along user‐selected closed curves. The scanning unit uses two galvanometer‐mounted mirrors for scanning. A standard procedure for recordings with this scanning unit would be to scan an overview image with conventional raster scanning to identify a region of interest, mark a point, a line, or a closed curve over this region, and to start the scanner. An iterating algorithm then calculates the waveforms needed by the scanner to follow the identified curves with pixel precision. With this scanning unit and its controlling software, experiments demanding time‐resolved recordings within the millisecond range can be performed. Repetition rates up to >1 kHz for line scanning and curve scanning, and >100 kHz for point scanning are obtainable. This allows time‐resolved studies of fast reactions in living tissue to be performed with the spatial resolution and signal‐to‐noise ratio obtainable with a point scanning confocal microscope.

The Kalman filter approach to inductively coupled plasma atomic emission spectrometry

This article is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta Part B (SAB). The hardcopy text, comprising the main article and two appendices, is accompanied by a disk containing the compiled program, a reference manual and data files. The work deals with data handling in inductively coupled plasma atomic emission spectrometry (ICP-AES). With this technique, the analyte signal is superimposed on a background signal. When separating the signals by manual or automated three-point background correction, there are many instances in which the data reduction fails. Based on scans recorded in a fast-scanning mode and on a library of pure-component scans, the Kaiman filter approach models the emission in the spectral window (about 100 pm) of the analyte and mathematically solves the problem of background correction. By using a criterion-based algorithm to correct for optical instability, the uncertainty in the determination of the interferent line signal is eliminated. Therefore, the present filter implementation yields more accurate and precise results, especially in the case of line overlap. The Kalman filter Approach to Atomic Spectrometry (KAAS) software automatically processes Perkin-Elmer Plasma 1000 2000 text files, but can also handle ASCII data files. Practical and comprehensive examples are given to evoke the “Kalman filter feeling” in the crucial step of creating the emission model.

ＭＲＩによる顎関節部の画像診断

Magnetic resonance imaging (MRI) of the temporomandibular joints (TMJs) were studied in 58 craniomandibular disorder (CMD) patients and 5 normal volunteers, by taking eitherthe gradient echo or spin echo pulse sequence in combination with the single or dual surface coil.Furthermore, 3 subjects from both groups were also studied with arthrography. Results showedboth the MRI and arthrography to have the same findings in regard to the condyle-disk relationshipat both positions of the mouth closing and opening among the 6 subjects.Although the MRI had previously been thought to provide no evidence of disk adhesion in theupper joint compartment, cine MRI induced by a fast-scan mode enabled us to distinguish those diskswith adhesion from those without. Direction of the disk displacements were judged by combiningthe MRI on the coronal and sagittal planes. The bilateral simultaneous cine MRI was thought tobe of help in evaluating the coordination of the condyle movement associated with each disk.Utilizing the cine MRI with a dual surface coil seemed to have greater value not only in termsof screening TMJs, but also for evaluating the therapy needed for CMD patients.

Kalman filtering for data reduction in inductively coupled plasma atomic emission spectrometry

In ICP-AES, the analyte signal is superimposed on a background signal. When separating these signals, essentially by manual or automated three-point background correction, there are many instances in which the data reduction falls, e.g., with noisy analyte signals, nonlinear background signals, large and heavily structured background, and spectral interference. On the basis of scans in a fast scanning mode, the Kalman filter approach yields in all cases more accurate and precise results

Structural investigation of surfaces of blue bronze and hematite by scanning tunneling microscopy

Images of the surfaces of cleaved crystals of K0.3MoO3 (blue bronze) and α-Fe2O3 (hematite) have been obtained in air at room temperature using a scanning tunneling microscope in the fast scanning mode. The pictures show a resolution in the range of 0.5 nm and compare well with surface structures derived from the bulk crystal parameters.

ＳＴＭの高性能化と先端プロセスへの応用

A scanning tunneling microscope (STM) was developed to evaluate advanced device process which needs atomic or nm order control. The STM has an atomic resolution topographic imaging mode, a fast probe scanning and imaging mode, and a material characterization imaging mode. The features of the instrument are : (1) A conversion technology of tunneling current fluctuation to gap fluctuation for a high resolution STM image, (2) a correction technology of probe control error in fast scanning for an in-situ observation and (3) an AD-DA conversion technology to hold the probe position fixed for a Current Imaging Tunneling Spectroscopy (CITS). Various STM images support that the STM provides a high resolution (around 2 A in X and Y, and less than 0.1 A in Z), a fast imaging of 2 s/flame (150 A × 150 A) and simultaneous measurement of both STM image and current image. (7×7) reconstruction Si (111) surface VTR images, (√3 × √3) Au construction on Si (111), pn junction structure and the boundary, and groove shape and recorded pit structure in optical disc device are presented and discussed here. The STM is found to be feasible to evaluate an Molecular Beam Epitaxy (MBE) process, a fine pn junction and an ultra high packed structure.

Xenon enhanced dynamic computed tomography: multilevel cerebral blood flow studies.

Xenon enhanced computed tomography with a fast scanning mode and interscan table incrementation was used to derive local cerebral blood flow in a nonhuman primate 19 days following infarction. The in vivo autoradiographic methodology was used to derive blood flow in normal and diseased tissue at four different brain levels (slices) during a single inhalation study.

Fast Scanned Energy Beam Induced Explosive Crystallization of Ion Implantation Amorphized Poly and Single Crystal Silicon Substrates

ABSTRACTExplosive crystallisation induced by an electron beam and by a CW Ar+ laser operating in fast scanning mode is observed for the first time on amorphized silicon layers created by implantation on either polycrystalline films deposited on Si02 or single crystal silicon substrates. The grain structure in the explosive crescents is studied by preferential chemical etching in conjunction with Nomarski optical microscopy, SEM and TEM. The results are similar to the so-called solid-phase explosive crystallization previously observed in a-Si films deposited on glass substrates.

A primer in computed axial tomographic anatomy.: I. The epigastrium

The following scans (Figures 1-4) were made on an EMI Scanner CT5000 with a 160 • 160 matrix. This device utilizes a 10-degree, fan-shaped x-ray beam. Alter attenuation of this beam by tissues in its path, a primary array of 30 sodium iodide crystal detectors and photomultipliers measures the emergent x-rays. The x-ray source and the diametrically opposed detector array traverse linearly across the patient and then index through an arc of l0 degrees around the patient, before another linear traverse across the patient is initiated. This sequence is repeated 18 times for each scan; consequently, the latter includes the data gathered from 18 linear traverses spanning 180 degrees around the patient. The thickness of each transverse tomographic section is 13 ram. During each linear traverse, 18,000 density measuremerits are made, and, since each completed scan consists of 18 linear traverses, 324,000 density measurements are available fbr formulation of the final scan image. The latter is projected on a 160 x 160 matrix and is therefore made up of 25,600 picture elements (pixels). Scans for the illustrations were made in the slog' scan option (80 sec per scan) rather than in the fast scan mode (20 sec per scan) that is used in most clinical circumstances. The illustrations were derived from scans of the embalmed body of a 48-year-old male whose death was due to a cerebrovaseular accident. The entire trunk was scanned at I-cm intervals to assure overlapping tomographic sections. Appropriate marks were made on the skin to permit reasonable accuracy

Contrast optimization in matrix-addressed liquid crystal displays

In a fast-scan mode of addressing a matrix of m rows and n columns, in which the columns are scanned, contrast is optimized by maximizing the ratio of the rms voltage at a selected intersection to that at a nonselected one. A simple derivation shows that the address-pulse amplitude should be taken proportional to n1/2. We apply this result to the twisted nematic case.