Mechanical Scanning Device Research Articles

Target-surface multiplexed quantitative dynamic phase microscopic imaging based on the transport-of-intensity equation.

Microscopic phase digital imaging based on the transport of intensity equation, known as TIE, is widely used in optical measurement and biomedical imaging since it can dispense with the dependence of traditional phase imaging systems on mechanical rotational scanning and interferometry devices. In this work, we provide a single exposure target-surface multiplexed phase reconstruction (SETMPR) structure based on TIE, which is remarkably easy to construct since it directly combines a conventional bright-field inverted microscope with a special image plane transmission structure that is capable of wavefront shaping and amplification. In practice, the SETMPR is able to achieve dynamic, non-interferometric, quantitative refractive index distribution of both static optical samples and dynamic biological samples in only one shot, meaning that the only limitation of measuring frequency is the frame rate. By comparing the measurement results of a microlens array and a grating with a standard instrument, the quantitative measurement capability and accuracy are demonstrated. Subsequently, both in situ static and long-term dynamic quantitative imaging of HT22 cells were performed, while automatic image segmentation was completed by introducing machine learning methods, which verified the application prospect of this work in dynamic observation of cellular in the biomedical field.

DETERMINATION OF THE ACOUSTO-OPTICAL DEFLECTOR PARAMETERS FOR A LASER-RADIATION ROCKET GUIDANCE SYSTEM

The work is devoted to the development of an acousto-optic deflector for a laser-beam guidance system (LLSN) of missiles. LLSN is used in semiautomatic portable missile systems to destroy hostile targets of various types. An analysis of the methods for constructing such systems has shown that the most promising devices with pulse-code modulation using semiconductor pulsed lasers.
 The article provides a diagram and describes the principle of operation of the LLSN with pulse-code modulation. A problematic issue in the implementation of such a system is the development of a device for deflecting a laser beam, through which the missile is guided to a target. Scanning mechanical devices that are currently in use have a complex design, significant dimensions and weight, and limited performance.
 The article proposes to use an acousto-optic deflector to deflect the laser beam within the information field of the guidance system, which is devoid of these disadvantages, since it replaces the mechanical scanning device with an electronic one. The purpose of the article is to determine the main parameters of the acousto-optical deflector.
 The article discusses the principle of operation of an acousto-optic deflector. It is noted that glasses based on germanium chalcogenides, in particular, glass with the composition Ge2.17As39.13S58.70, have especially low values of acoustic losses (α <1 dB / cm).
 The largest deflection angle of the laser beam will be observed with Bragg diffraction. Relationships are given that can be used to determine the main characteristics of the deflector: the angle of deflection of the laser beam, the modulation frequency of the acoustic wave, resolution, speed, and others. When using the above ratios for the typical parameters of the existing guidance system, the values of the indicated characteristics are calculated.

Digital-micromirror-device-based surface measurement using heterodyne interferometry with optical frequency comb

We propose a surface measurement method based on optical frequency comb heterodyne interferometry ranging. A digital micromirror device is used to establish a single-pixel detection system without a mechanical scanning device and realize high-speed sampling. The measurement range of the step height is extended by synthetic wavelength interferometry from half of the carrier wavelength to half of the synthetic wavelength (40 μm in this system). Thus, a sample composed of three gauge blocks and an MEMS device of the teardrop-shaped groove were measured with an accuracy of 5 nm and a measurement time of 27 ms.

Optical Probe Capable of Side View Optical Imaging Without Mechanical Scanning Device

Optical Probe Capable of Side View Optical Imaging Without Mechanical Scanning Device

Design and Development of a Mechanical Linear Scanning Device for the Three-Dimensional Ultrasound Imaging System

Design and Development of a Mechanical Linear Scanning Device for the Three-Dimensional Ultrasound Imaging System

An active hyperspectral imaging system based on a multi-LED light source.

Hyperspectral imaging (HSI) is a popular method of substance identification and mapping in many fields. Light-emitting diodes (LEDs) can be introduced as an active light source, which have been widely used with the distinct advantages of small size, low energy consumption, long lifetime, and fast switching. In this paper, we propose an active HSI system that is based on a multi-wavelength LED-array light source. This LED-based HSI system has a simple and stable configuration, without the complex dispersive spectrometer and mechanical scanning device. The proposed HSI system has been validated using the standard color checker, showing a reliable spectral performance. Moreover, the spatial-spectral information of Chinese paper-cuttings has been successfully extracted, which indicates the great potential in practical applications.

Femtosecond laser-based phase-shifting interferometry for optical surface measurement.

This paper demonstrates an unequal-path phase-shifting interferometer for precise optical surface measurement using a femtosecond laser. According to the periodic low temporal coherence of the femtosecond laser, the relative time delay between pulses from the reference and target surfaces is scanned by sweeping the repetition frequency for phase shifting when the optical path length difference is set to integer times of the pulse interval, which removes mechanical scanning devices in the interferometer. In particular, we employ an iterative least-squares fitting algorithm to derive the phase. With this method, a glass slide surface is reconstructed that agrees well with the surface measured using a commercial Fizeau interferometer. The comparison results show that the difference in the peak-to-valley value is 0.050 μm.

Development of a Mechanical Scanning Device With High-Frequency Ultrasound Transducer for Ultrasonic Capsule Endoscopy.

Wireless capsule endoscopy has opened a new era by enabling remote diagnostic assessment of the gastrointestinal tract in a painless procedure. Video capsule endoscopy is currently commercially available worldwide. However, it is limited to visualization of superficial tissue. Ultrasound (US) imaging is a complementary solution as it is capable of acquiring transmural information from the tissue wall. This paper presents a mechanical scanning device incorporating a high-frequency transducer specifically as a proof of concept for US capsule endoscopy (USCE), providing information that may usefully assist future research. A rotary solenoid-coil-based motor was employed to rotate the US transducer with sectional electronic control. A set of gears was used to convert the sectional rotation to circular rotation. A single-element focused US transducer with 39-MHz center frequency was used for high-resolution US imaging, connected to an imaging platform for pulse generation and image processing. Key parameters of US imaging for USCE applications were evaluated. Wire phantom imaging and tissue phantom imaging have been conducted to evaluate the performance of the proposed method. A porcine small intestine specimen was also used for imaging evaluation in vitro. Test results demonstrate that the proposed device and rotation mechanism are able to offer good image resolution ( [Formula: see text]) of the lumen wall, and they, therefore, offer a viable basis for the fabrication of a USCE device.

A surface plasmon resonance imaging system for the stimulated living cell analysis

In this paper, a surface plasmon resonance imaging (SPRI) system for cell analysis is developed for obtaining the surface plasmon resonance (SPR) signal from the interactions between cells and different stimuli. The system is constructed with a red laser light source, a P-polarizer, a glass prism, a 5× objective lens, a charge coupled device (CCD) camera, a gold sensor chip, a polydimethylsiloxane (PDMS) reaction well and a mechanical scanning device. The system is applied to mapping living cells in response to stimuli by characterization of the refractive index (RI) changes. Cell responses to K+ in KCl solutions with concentrations of 5 mmol/L, 20 mmol/L, 50 mmol/L and 100 mmol/L are collected, which indicates that the SPRI method can distinguish the concentration of the stimuli. Furthermore, cell responses to epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) are studied independently. The binding of EGF receptor (EGFR) and EGF is collected as the first signal, and the internal change in cells is recorded as the second signal. The cell response to VEGF is different from that to EGF, which indicates that the SPRI as a label-free, real-time, fast and quantitative method has a potential to distinguish the cell responses to different stimuli.

Development of dual‐channel surface plasmon resonance imaging system applied to living tumour cell analyses

Presented is homemade dual-channel surface plasmon resonance (SPR) imaging (SPRI) system enabling living cell analysis in various stimuli based on refractive index (RI) variations. The system was constructed with a laser source of 650 nm, a P-polariser, a glass prism, an objective lens, a CCD camera, a dual-channel gold sensor chip, a dual-channel PDMS flow cell and a mechanical scanning device. Living human type II alveolar epithelial cell line A549 cells were cultured on the surface of a gold sensor chip. Different solutions were loaded into two independently parallel flow channels to make comparison of the cells’ reaction results. Cells' responses in both the testing and the reference channels with and without K+ stimuli were collected. Furthermore, the epidermal growth factor (EGF) was loaded to stimulate cells in the testing channel while a mixture of EGF and Iressa (ZD1839) were loaded in the reference channel. The SPR response signal was different from the two channels, which indicated that Iressa as an EGFR inhibitor effectively inhibited the signal transduction of the EGF and EGFR bonding process of A549 cells. The use of the dual-channel SPRI system to study the behaviour of living cells to stimuli is of great help in understanding the life activities of living cells.

Finite Element Dynamic Analysis of the Shafting of Transmission-Laser-Scanning-Emitter

The transmission laser-scanning diameter-measurement system uses the parallel laser-scanning principle to achieve high-precision measurements of radial dimensions of shaft parts. The transmission laser-scanning emitter is a mechanical scanning device of which scanning accuracy has a significant impact on stability of the measurement system. The dynamic model of the emitter's shaft rotor is established. Dynamic performances according to variant parameters are derived by finite element analysis simulation. Characteristics of high-speed-rotors with different structures, such as vibration mode and natural frequency, are summarized to provide theoretical basis for shafting design.

Study on Precision Scanning Measurement Based on Acousto-Optic Deflection Technology

Scanning measurement is a basic means to achieve high precision geometric measurement. However, the scanning device has a congenital defect which is the presence of a mechanical scanning device, thus, it has some issues such as wear, vibration, temperature sensitive.This articlecreatively put forward a kind of control method which is using acousto-optic deflection technology to realize the laser scanningfrom the general character of scanning measurement.The method has the advantages of the principle, it eliminatestheinherent defect of rotary machine structure on the measurement accuracy, speed, controllability, and stability. The exploration and research of this method will provides a new non inertial rotation scanning means for optical scanning measurement. More important, the implementation of the method will provides a new thought and method for the kind of problem about beam scanning measurement of geometric measurement.

On the efficacy of spatial sampling using manual scanning paths to determine the spatial average sound pressure level in rooms

In architectural acoustics, noise control and environmental noise, there are often steady-state signals for which it is necessary to measure the spatial average, sound pressure level inside rooms. This requires using fixed microphone positions, mechanical scanning devices, or manual scanning. In comparison with mechanical scanning devices, the human body allows manual scanning to trace out complex geometrical paths in three-dimensional space. To determine the efficacy of manual scanning paths in terms of an equivalent number of uncorrelated samples, an analytical approach is solved numerically. The benchmark used to assess these paths is a minimum of five uncorrelated fixed microphone positions at frequencies above 200 Hz. For paths involving an operator walking across the room, potential problems exist with walking noise and non-uniform scanning speeds. Hence, paths are considered based on a fixed standing position or rotation of the body about a fixed point. In empty rooms, it is shown that a circle, helix, or cylindrical-type path satisfy the benchmark requirement with the latter two paths being highly efficient at generating large number of uncorrelated samples. In furnished rooms where there is limited space for the operator to move, an efficient path comprises three semicircles with 45°-60° separations.

Opening of the Blood-Brain Barrier by Low-Frequency (28-kHz) Ultrasound: A Novel Pinhole-Assisted Mechanical Scanning Device

Disruption of the blood-brain barrier (BBB) may be transiently achieved via high-frequency focused spherical ultrasound in the presence of microbubbles. In this experimental animal study, we sought to determine whether focal reversible opening of the BBB may be achieved using low-frequency ( i.e., 20–30 kHz) planar ultrasonic waves. In the presence of microbubbles, we were able to obtain BBB opening using non-focused ultrasound irradiation with a frequency as low as 28 kHz. We also achieved a tight regulation of the ultrasound patterns by using a mechanical scanning device equipped with a pinhole. Histologic examination of the brains supported the feasibility of our system. The areas of BBB disruption obtained with this method were large enough to cover a typical circumscribed cerebral tumor mass. The inherent advantages of our BBB opening method include an improved portability, the possibility to obtain fairly wide areas of BBB opening and a low incidence of hemorrhagic complications. In addition, our system has the potential to reduce the need for image guidance for treating superficial brain lesions. (E-mail: haoliliu@mail.cgu.edu.tw).

Digital micromirror device for optical scanning applications

Recent mechanical and nonmechanical optical scanning devices do not meet the fast scanning requirements for contemporary and emerging applications and can only steer optical beams over relatively narrow angles. A variety of important applications require fast optical scanning devices that can steer laser beams rapidly to an arbitrary location and with no moving parts. We introduce a new optical scanning technique that can be used to collimate and steer optical beams for precision alignment in either 2-D free-space optical (FSO) communications links or image scanners. This nonmechanical technique is capable of rapidly redirecting the optical beams to arbitrary locations without greatly sacrificing other parameters such as aperture size, efficiency, and scanning range. A digital micromirror device (DMD) beam-steering system was successfully demonstrated and exhibited better performance results when compared with other available systems.

Integration of Organic FETs With Organic Photodiodes for a Large Area, Flexible, and Lightweight Sheet Image Scanners

A large-area, flexible, and lightweight sheet image scanner has been successfully manufactured on a plastic film by integrating high-quality organic transistors and organic photodetectors. The effective sensing area of the integrated device is 5/spl times/5 cm/sup 2/; the resolution, 36 dots per inch (dpi); and the total number of sensor cells, 5184. The pentacene transistors with top contact geometry have a channel length of 18 /spl mu/m and mobility of 0.7 cm/sup 2//Vs. Organic photodetectors composed of copper phthalocyanine and 3,4,9,10-perylene-tetracarboxylic-diimide distinguish between black and white parts on paper based on the difference in their reflectivity. Since this new area-type image-capturing device does not require any optics or mechanical scanning devices, the present sheet image scanners are mechanically flexible, lightweight, shock resistant, and potentially inexpensive to manufacture; therefore, they are suitable for human-friendly mobile electronics.

Mechanical scanning of the specimen in the scanning electron microscope

A scanning electron microscope (SEM) system equipped with a motor drive specimen stage fully controlled with a personal computer (PC) has been utilized for obtaining ultralow magnification SEM images. This modem motor drive stage works as a mechanical scanning device. To produce ultra-low magnification SEM images, we use a successful combination of the mechanical scanning, electronic scanning, and digital image processing techniques. This new method is extremely labor and time saving for ultra-low magnification and wide-area observation. The option of ultra-low magnification observation (while maintaining the original SEM functions and performance) is important during a scanning electron microscopy session.

Depth-resolved whole-field displacement measurement using wavelength scanning interferometry

We describe a technique for measuring depth-resolved displacement fields within a three-dimensional (3D) scattering medium based on wavelength scanning interferometry. Sequences of two-dimensional interferograms are recorded whilst the wavelength of the laser is tuned at a constant rate. Fourier transformation of the resulting 3D intensity distribution along the time axis reconstructs the scattering potential within the medium, and changes in the 3D phase distribution measured between two separate scans provide one component of the 3D displacement field. The technique is illustrated with a proof-of-principle experiment involving two independently controlled reflecting surfaces. Advantages over the corresponding method based on low-coherence interferometry include a depth range unlimited by mechanical scanning devices, and immunity from fringe contrast reduction when imaging through dispersive media.

A new computer-controlled surface-scanning device for measurement of fracture surface roughness

This paper introduces the design of a new computer-controlled fracture surface mapping system. The system consists of a mechanical scanning device, a circuit, a PC and software to control the unit automatically. The system is especially suited for scanning small core-size samples and capable of collecting data on a 54×54 mm area with maximum 1 mm resolution in the x– y direction and 0.1 mm in the z direction. A full description of the system units and the software are given. The 3-D images and contour maps of synthetic and natural fracture surfaces are also provided. The fractal analysis of data reveals that the surface data acquired are suitable for quantitative analyses.

EUS instrumentation and accessories: A primer

Advances in therapeutic interventional EUS and new applications for EUS have led to a number of new devices and accessories for EUS. US systems currently available for endoscopic applications include those that are endoscope-based and those that are catheter-based. The endoscope-based systems are of two basic design types: mechanical radial scanning devices and electronic curved array devices. This article provides an overview of the currently available devices as well as those in development.