Continuous Scanning Method Research Articles

Continuous Scanning and Inching in Ultrasonographic Localisation of Ulnar Neuropathy: A Comparative Study of Sensitivity.

Background: This study compares the sensitivity of continuous ultrasonographic scanning and ultrasonographic inching in the localisation of ulnar neuropathy at the elbow to diagnose the two common entrapment sites: retroepicondylar groove and cubital tunnel. Methods: The charts of 30 patients who were diagnosed with ulnar neuropathy of the elbow and underwent ultrasonographic examinations using the inching and the continuous technique between April 2015 and September 2019 were reviewed. Sensitivities of ultrasonographic inching and continuous scanning were compared. Results: A total of 34 elbows from 30 patients were examined. The sensitivities of continuous ultrasonographic scanning method and ultrasonographic inching were 85% and 71%, respectively, but this was not significant (p = 0.06). The maximum cross-sectional areas (CSAs) in continuous scanning were mainly found within the area from the medial epicondyle to the 2-cm distal point in the cubital tunnel entrapment, while a majority of the largest CSAs in ultrasonographic inching was observed at the medial epicondyle level in both entrapment sites. The mean of the maximum CSAs in continuous scanning (17.04 ± 6.75 mm2) was higher than that in ultrasonographic inching (14.13 ± 6.63 mm2), although this difference remained non-significant (p = 0.08). However, continuous scanning differed more significantly (p < 0.0001) from the cut-off value than the ultrasonographic inching (p < 0.0066). Conclusions: Continuous scanning might be more suitable than ultrasonographic inching to localise ulnar neuropathy, which inherently has variations in the cubital tunnel anatomy and its entrapment points, when selecting optimal treatment based on the entrapment site. Level of Evidence: Level III (Diagnostic).

Optimized Chaotic encrypted image based on continuous raster scan method

As the greatest effective method of protection of multimedia data is image encryption is extensively used in data hiding, security authentication and content protection. Nevertheless, the security and efficiency are still the key issues of image encryption algorithm. However, the existing image encryption techniques face the issues namely poor resistance to plaintext attacks, simple algorithmic structures and small key space. In order to overcome the problem of traditional techniques, a joint image encryption techniques of continuous raster Scan, Henon Chaotic Map and Chebyshev Chaotic Map are developed for providing a security of images. Initially, the continuous raster is used to scramble the pixels of each blocks, where images are partitioning an image into non overlapping blocks and starting point is randomly selected in Henon Chaotic Map to permute the block. To calculate a random matrix, Chebyshev Chaotic Map is used to generate the sequence based on the secret keys. Finally, bitwise XOR operation between the scrambled image and random matrix is conducted to obtain the encrypted image. The proposed method takes very less time for encryption. Simulation results show that the algorithm is efficient and usable for the security of the image encryption system.

3차원 마이크로 세포칩 제작을 위한 3차원 연속 레이저 스캐닝 방법

Nanostereolithography induced by a femtosecond laser is widely used for fabrication of three-dimensional (3D) microstructures with submicron resolutions. In this study, we propose a 3D continuous laser scanning method for an effective direct writing of 3D microstructures. The advantages of the 3D continuous laser scanning method are analyzed by considering its high resolution, time economy, and fabrication effectiveness. As the 3D continuous laser scanning is an efficient manufacturing method, which can immediately respond to a complex 3D structure, it could be used for various applications including platforms for cell culture, metamaterials, and functional sensors. In this paper, the 3D open cell structure was fabricated and cells are cultured on the structure for microcell chip application.

Spatial distribution and content detection of gefitinib in tablets using confocal micro-raman spectroscopy mapping

In this study, we aim at establishing a method to evaluate the spatial distribution and content of gefitinib in tablets without destroying the tablets. The content of gefitinib tablets was determined by HPLC. Using confocal micro-Raman spectroscopy, with a wavelength of 785 nm and power of 10%, gefitinib, starch, and hydrated magnesium silicate were scanned. Tablets with five concentrations of gefitinib (15.63–31.25%) were scanned with a 1000 × 1000 μm spectral resolution and live video imaging was performed. The surfaces of gefitinib tablets were scanned and images were obtained by a continuous scanning method. Characteristic Raman spectra of tablets were obtained after surface scanning and map reviews of tablets with five concentrations of gefitinib for rapid and accurate identification. The characteristic spectral bands of gefitinib, starch, and hydrated magnesium silicate were 1620 cm–1, 480 cm–1, 1350 cm–1 respectively. Comparing the surfaces of the tablets, it was found that the tablets with a flat and round surface are more suitable for Raman spectroscopy. Live video imaging and scanning maps of five concentrations of gefitinib were performed. The results showed that the product with the content of 16.12% had a good mixing homogeneity. In conclusion, confocal micro-Raman spectroscopy can detect the spatial distribution and content of gefitinib tablets without destroying tablets.

A phase-sampling method for an X-ray Talbot-Lau scanner with continuous grating movement

A Talbot-Lau scanner enables fast grating-based X-ray phase-contrast and dark-field imaging of large samples. We present a fast and robust scanning method based on continuous phase-sampling during the usual scan process. For that purpose the source grating is moved back and forth during the whole image acquisition procedure. The scanning method needs no specific detuning of the interferometer. The acquired images are compared to the results of a standard phase-stepping procedure. We show that high quality images are obtained by this continuous phase-sampling scanning method. One main advantage of the method is its independence of the occurring moir'e pattern shape, thus enabling an optimal alignment of the interferometer. Furthermore, the method works with a priori unknown phase-step positions. To our knowledge, this is the first time a grating is moved continuously back and forth while also the sample is in linear motion during a continuous image acquisition in Talbot-Lau imaging.

Экспериментальное исследование деформативности предварительно напряженных многослойных деревоплит методом сплошного лазерного сканирования

Экспериментальное исследование деформативности предварительно напряженных многослойных деревоплит методом сплошного лазерного сканирования

Using a New Magnetic Flux Leakage Method to Detect Tank Bottom Weld Defects

Background: The weld is an important connection part of the tank bottom but during the process of manufacturing and through its use, it frequently produces defects and brings serious hidden danger in the process of safety production. Objective: This paper develops a new magnetic flux leakage testing system for tank bottom weld defects and proposes an extraction method for the weld defect. It can be used in the detection and visual evaluation of the weld defects. Method: A continuous non-contact scanning method is used in the rectangular slot defect in the different regions of the weld by using a new magnetization system that is vertical to the travelling direction. The characteristics of the weld and the defect are transformed into accurate two-dimensional grayscale graphics through grayscale linear transformation. This is done through the combination of histogram equalization, Otsu’s method of binaryzation, morphologically removing small objects, edge detection, and then structuring a morphologically optimized edge extraction algorithm for edge detection on the grayscale. The displayed grayscale outline locates and quantifies the defects. Conclusion: The results indicated that this method can directly indicate the defect shape, location and other information, the visual display of the magnetic flux leakage testing of the weld defects was also realized. It solved difficulties associated with the magnetic flux leakage method being used in the weld testing and showed how weld detection equipment can be used in the detection and visual evaluation of the weld defects.

Scaling laws of nanorods in two-photon polymerization nanofabrication using a continuous scanning method

We report on the scaling laws of nanorods in two photon polymerization nanofabrication using a continuous scanning method. We focus on a cross-sectional plane of a nanorod to investigate how a moving laser focal spot effects on the photoresist. Under a hypothetical polymerizing threshold of free radicals concentration, lateral and vertical size models were established by transforming the continuously changing photon intensity to an equivalent constant value. A transformational relationship of voxels and nanorods with a same lateral size is deduced to validate the proposed models. In the experiment, voxels were obtained by an ascending scan method while nanorods were fabricated by a cantilever method. The experimental data shows a good agreement with predicted data.

Mobile robot vision system using continuous laser scanning for industrial application

Purpose The purpose of this paper is the presentation and research of a novel robot vision system, which uses laser dynamic triangulation, to determine three-dimensional (3D) coordinates of an observed object. The previously used physical operation principle of discontinuous scanning method is substituted by continuous method. Thereby applications become possible that were previously limited by this discretization. Design/methodology/approach The previously used prototype No. 2, which uses stepping motors to realize a discontinuous laser scan, was substituted by the new developed prototype No. 3, which contains servomotors, to achieve a continuous laser scan. The new prototype possesses only half the width and turns out to be significantly smaller and therefore lighter than the old one. Furthermore, no transmissions are used, which reduce the systematic error of laser positioning and increase the system reliability. Findings By using a continuous laser scan method instead of discontinuous laser scan method, dead zones in the laser scanner field can be eliminated. Thereby, also by changing the physical operation principle, the implementation of applications is allowed, which previously was limited by the fixed step size or by the object distance under observation. By using servomotors instead of stepping motors, also a significant reduced positioning time can be accomplished maintaining the relative positioning error less than 1 per cent. Originality/value The originality is based on the substitution of the physical operation principle of discontinuous by continuous laser scan. The previously used stepping motors discretized the laser scanner field and thereby produced dead zones, where 3D coordinates cannot be detected. These stepping motors were substituted by servomotors to revoke these disadvantages and provide a continuous laser scan, where dead zones in the field of view get eliminated and the step response of the laser scanner accelerated.

A High-Resolution Continuous-Scan Acoustic Measurement Method for Turbofan Engine Applications

Detailed mapping of the sound field produced by a modern turbofan engine, with its multitude of overlapping noise sources, often requires a large number of microphones to properly resolve the directivity patterns of the constituent tonal and broadband components. This is especially true at high frequencies where the acoustic wavelength is short, or when shielding, scattering, and reflection of the sound field may be present due to installation effects. This paper presents a novel method for measuring the harmonic and broadband content of complex noncompact noise sources using continuously moving (referred to here as continuous-scan (CS)) microphones in conjunction with a state-of-the-art phase-referencing technique. Because the microphones are moving through the sound field produced by the noise sources, they effectively provide infinite spatial resolution of the sound directivity over the scan path. In this method, harmonic (i.e., shaft-coherent) content at the integer multiples of the instantaneous shaft rotational frequency is first extracted from the time signal using a tachometer signal and the Vold-Kalman (VK) filter. The residual broadband signal is then filtered in the time domain in fractional octave bands. The broadband spectra of the signals from the moving microphones are then computed at arbitrary positions along their scan paths using weighted averages (based on Chebyshev polynomial zero-crossings) and the assumption of a complex envelope that varies slowly over a spatial scale whose lower bound is set by the acoustic wavenumber. A benefit of this method is that the decomposition of the total measured sound field into a stochastic superposition of components preserves a meaningful phase definition for each “partial field” associated with a given shaft order (SO). This preservation of phase data enables the forward or backward projection of each of these partial fields using acoustical holography (AH). The benefits of the CS method are demonstrated using acoustic data acquired for a 22-in. scale-model fan stage run at the NASA Glenn Research Center's 9-foot by 15-foot wind tunnel. Two key outcomes of the work include (1) significant improvement in the spatial resolution of the measured sound field and (2) reduction in the overall data acquisition time. Additionally, the methods described here lead to new opportunities for noise source diagnostics and visualization.

Development of a 3D optical scanner for evaluating patient-specific dose distributions

PurposeThis paper describes the hardware and software characteristics of a 3D optical scanner (P3DS) developed in-house. The P3DS consists of an LED light source, diffuse screen, step motor, CCD camera, and scanner management software with 3D reconstructed software. Materials and methodWe performed optical simulation, 2D and 3D reconstruction image testing, and pre-clinical testing for the P3DS. We developed the optical scanner with three key characteristics in mind. First, we developed a continuous scanning method to expand possible clinical applications. Second, we manufactured a collimator to improve image quality by reducing scattering from the light source. Third, we developed an optical scanner with changeable camera positioning to enable acquisition of optimal images according to the size of the gel dosimeter. ResultsWe confirmed ray-tracing in P3DS with optic simulation and found that 2D projection and 3D reconstructed images were qualitatively similar to the phantom images. For pre-clinical tests, the dose distribution and profile showed good agreement among RTP, optical CT, and external beam radiotherapy film data for the axial and coronal views. The P3DS has shown that it can scan and reconstruct for evaluation of the gel dosimeter within 1 min. We confirmed that the P3DS system is a useful tool for the measurement of 3D dose distributions for 3D radiation therapy QA. Further experiments are needed to investigate quantitative analysis for 3D dose distribution.

Fabrication of 15 nm curvature radius polymer tip probe on an optical fiber via two-photon polymerization and O2-plasma ashing

Polymer tips with 15 nm curvature radius apexes that are capable of scanning the surface of a sample have been fabricated on the surface of an optical fiber using two-photon photopolymerization (TPP) and O2-plasma ashing with a SCR500 resin. First, the parent conical polymer tip with a 125 nm curvature radius apex was fabricated via TPP using a continuous scanning method and the accumulation of circular layers. Next, the tip was sharpened using an O2-plasma ashing process with high reproducibility. As a result, the apex radius of curvature had a maximum reduction to 15 nm. In order to evaluate the performance of the 15 nm curvature radius polymer tip, a 30 nm thick gold layer with holes of 250 nm radius and a single layer of polystyrene beads with a 350 nm radius were imaged using a tuning-fork-based atomic force microscope. The topographic images obtained by the 15 nm polymer tip were improved in width and depth compared with those obtained by the 125 nm polymer tip due to the reduction of the imaging artifacts. This method can also be commonly used to reduce the radius of curvature of the polymer tip in order to achieve more accurate imaging.

Study of Double-Sided Welding Defect Detection Technique Based on the Method of Magnetic Flux Leakage

This paper presents a new approach based on the method of magnetic flux leakage (MFL) for the double-sided butt weld (DSBW) of the welding equipment such as the pressure vessel in order to detect and identify the weld defect. In this approach, a new magnetization structure is adopted whose magnetization direction is perpendicular to weld line, also, a new continuous non-contact scanning method is used, what aims to solve the problems about complex leakage magnetic field (LMF) space distribution. Then, the LMF distribution laws with non-defect (ND) and laws with precrack from heat affected zone (PFHAZ) are obtained through using these methods such as theoretical analysis, numerical simulation, and experimental study. Afterwards, this paper reviews the recognition analysis of the above-mentioned two kinds of state (ND and PFHAZ) by binding the contrastive curves. The outcomes indicate that the suggested method of MFL has realized the recognition of ND and PFHAZ; The numerical simulation results and experimental results match each other well and their correlation coefficient R is 0.9729. Furthermore, the results verify the feasibility and the validity for the suggested method. This is a new way for exploration detection of the double-sided butt weld.

High Performance Human Face Recognition using Gabor Based Pseudo Hidden Markov Model

This paper introduces a novel methodology that combines the multi-resolution feature of the Gabor wavelet transformation (GWT) with the local interactions of the facial structures expressed through the Pseudo Hidden Markov Model (PHMM). Unlike the traditional zigzag scanning method for feature extraction a continuous scanning method from top-left corner to right then top-down and right to left and so on until right-bottom of the image i.e., a spiral scanning technique has been proposed for better feature selection. Unlike traditional HMMs, the proposed PHMM does not perform the state conditional independence of the visible observation sequence assumption. This is achieved via the concept of local structures introduced by the PHMM used to extract facial bands and automatically select the most informative features of a face image. Thus, the long-range dependency problem inherent to traditional HMMs has been drastically reduced. Again with the use of most informative pixels rather than the whole image makes the proposed method reasonably faster for face recognition. This method has been successfully tested on frontal face images from the ORL, FRAV2D, and FERET face databases where the images vary in pose, illumination, expression, and scale. The FERET data set contains 2200 frontal face images of 200 subjects, while the FRAV2D data set consists of 1100 images of 100 subjects and the full ORL database is considered. The results reported in this application are far better than the recent and most referred systems.

Fabrication of sharp-needled conical polymer tip on the cross-section of optical fiber via two-photon polymerization for tuning-fork-based atomic force microscopy

Aiming at the use in tuning-fork-based atomic force microscopy (TF-based AFM), we propose and demonstrate fabrication methods of polymer tips on the cross-section of optical fibers by two-photon polymerization (TPP) using SCR500 resin. This method can be applied to any optical fibers or other bases regardless of the type. The specified polymer tips are fabricated with high reproducibility by this method. First, a conical polymer tip was fabricated via a continuous-scanning method and layer-by-layer accumulation of circular layers which reduce to a point along with the growth from the cross-section of optical fibers, by using a five-axis optical fiber mount combined with a two-photon nanofabrication system. A sharp-needled conical polymer tip of a 45nm radius of curvature was fabricated with attachment of four voxels. These voxels were fabricated by the gradually-decreasing-exposure-time method on the apex of the simple conical tip. We have also designed and fabricated a triple-tapered polymer tip to demonstrate the feasibility of fabricating various tip shapes by the TPP method for the TF-based AFM. Moreover, the photoluminous polymer tip was fabricated using ORMOCER mixed with quantum dots. The sharp-needled polymer tip was utilized for the TF-based AFM using an optical fiber probe to investigate the performance of the polymer tip fabricated by the TPP method, and we have obtained a topographic image of a pitted sample. Finally, the near-field image of the 30-nm-thick gold layer with holes of 250-nm-radius was successfully obtained by the aluminum-coated NSOM probe fabricated on the TPP conical polymer tip with a radius of curvature of 45nm in NSOM system.

INVESTIGATION OF SPACE CHARGE TRAP LEVELS IN Al2O3 NANO-POWDER DOPED POLYETHYLENE BY PHOTO-STIMULATED DISCHARGE METHOD

The trap levels of Al 2 O 3 nano-powder doped LDPE with different Al 2 O 3 contents are investigated by PSD technique. The variation of trap depth in the doped LDPE can be qualitatively estimated by PSD spectra in continuous scanning method, and the distribution of trap levels in the samples can be quantitatively described in step scanning method. It is indicated that the trap levels of LDPE can be evidently deepened by Al 2 O 3 nano-powder doping with the content more than 0.1 wt%. According to the relative reports on the effect of nano-powder doping to space charge injection, it is considered that the suppression of space charge is probably correlated to the deeper trap levels in Al 2 O 3 nano-powder doped LDPE.

Continuous Scan, a method for performing modal testing using meaningful measurement parameters; Part I

This paper presents the first part of a work about modal testing using meaningful measurement parameters. Scanning Laser Doppler Vibrometer (SLDV) systems are becoming largely used both in industry and university for performing vibration measurements. A reason for the success of SLDV systems can be found in their capability of measuring vibration remotely and under different environmental conditions which, when hostile, can inhibit other transducers to work correctly. Hence, SLDV system can be very practical and useful in many engineering applications. SLDV systems are being used as a contactless transducer measuring vibrations from a discrete number of measurement positions marked on the specimen whenever an optical access to it is available. Hence, the advantage of a modal test carried out using accelerometers and one carried out using a SLDV system can be: (i) the automation of the measurements and (ii) the increase of the spatial resolution of the measured modes. This suggests that SLDV systems can be used as a practical replacement of accelerometers operating the same measurement method. Continuous Scanning method is a novel approach of using contactless transducers for measuring vibrations. The most important difference between a discrete and a continuous approach is the method of measuring a vibration pattern. A discrete method measures the level of vibrations at discrete positions on a structure whereas a continuous method captures the modulation of the vibrations produced by the excited modes. This is possible when a transducer can travel across a vibrating surface. This first part of the work presents a new approach of continuous scanning measurement method using a multi-tonal excitation waveform. The paper starts from a comparison between a step and continuous scan mode to introduce a novel approach of continuous scan and multi-tonal excitation waveform. The objective of this first part of work is to present and understand that measurement parameters, such as measurement positions, and can be carefully chosen to improve the measurement technique. A laboratory test piece and a helicopter tail cone are used as examples for the application of this new measurement method approach.

Clinical Value of Continuous Scanning Method of Ultrasound in Orlentaflonal Diagnosis of Obstructive Jaundice

Objective To evaluate clinical value of Continuous Scanning Method(CSM) of ultrasound in orientational diagnosis of obstructive iaundice.Methods 83 cases of obstructive iaundice were examined by Ultrasound with CSM.The results were compared with operation and pathology.Results In 83 cases of obstructire iaundice,the positions of obstructive were 5 in hepatic duct,37 in mesomere bile duct and 41 in inferior bile duct.According to the operation results,79 were coincident.The coincidence rate was 95.2% (75/83).Conclusion The CSM of ultrasound has important value in orientational diagnosis of obstructive iaundice. Key words: Continuous Scanning Method(CSM); Obstructive Jaundice; Ultrasonography; Orientational Diagnosis

Highly effective three-dimensional large-scale microfabrication using a continuous scanning method

Effective scanning is an important issue in two-photon induced stereolithography (TPS) for the reduction of the processing time required to fabricate three-dimensional (3D) nano/microstructures. In large-scale TPS based on a stage-scanning system, the large processing time due to the intrinsic slow response in the stage scanning system is a major obstacle to its use as a practical nanofabrication process. To overcome this drawback, we propose a continuous scanning method (CSM) for a stage-scanning system. In CSM, a pattern is generated with continuous movement of the stage during laser beam exposure. A stable fabrication window (SFW), which enables uniform motion of the stage without errors considering the stage characteristics, was obtained from fundamental experiments. Within the condition of a SFW, 2D and 3D microstructures having nanoscale details were fabricated with a whole scale range of several hundred micrometers using CSM.

연속적 스캐닝 방법을 이용한 이광자 광중합 공정의 제작 속도 및 정밀도 개선에 관한 연구

Abstract Minimization of processing time in two-photon stereolithography (TPS) has been one of important issues. Generally, a voxel scanning method (VSM) has been used in TPS because the method is very profitable for the stable fabrication irrespective of jittering and response time of scanning equipments such as a stage and a galvano-scanner. However, supplementary processing time due to the on/off control of a shutter for the generation of each voxel is required inevitably in VSM; by this reason, much processing time takes to fabricate largescale micropatterns and three-dimensional patterns. In this work, a continuous scanning method (CSM), generating patterns by movement of beam focus with a constant speed, is proposed for the improvements of scanning speed and precision in TPS. Some line patterns are fabricated by each scanning method to demonstrate the usefulness of CSM with viewpoints of scanning speed and precision. 1. 서 론 이광자 흡수 광중합 현상(two-photon iniduced photo-polymerization)을 이용한 나노 스테레오 리소그래피 공정은 극소형의 완전한 3 차원 형상을 제작할 수 있는 가장 유리한 방법 중 하나로 인식되고 있다.