Background: A Hartmann operation, which is the intervention by which the lower part of the sigmoid and the upper part of the rectum are resected with the closing of the rectal stump and end colostomy, has as its indications: advanced or complicated r...
In this work, an adaptive Hartmann–Shack wavefront sensor (AHSS) is proposed, designed, and evaluated. This sensor allows for the modification in the dynamic range of wavefront aberration measurement, defined as the range between the minimum an...
Aiming at the problem that it is difficult for the conventional Shack–Hartmann wavefront sensor to achieve high-precision wavefront reconstruction with low spatial sampling, a kind of Shack–Hartmann wavefront sensing technology based on f...
Light beams carrying Orbital Angular Momentum (OAM), also known as optical vortices (OV), have led to fascinating new developments in fields ranging from quantum communication to novel light–matter interaction aspects. Even though several techn...
New, high-coherent-flux X-ray beamlines at synchrotron and free-electron laser light sources rely on wavefront sensors to achieve and maintain optimal alignment under dynamic operating conditions. This includes feedback to adaptive X-ray optics. We d...
The effect of a transverse magnetic field on two-phase stratified flow in horizontal and inclined channels is studied. The lower heavier phase is assumed to be an electrical conductor (e.g., liquid metal), while the upper lighter phase is fully diele...
Virtual Shack–Hartmann wavefront sensing (vSHWS) can flexibly adjust parameters to meet different requirements without changing the system, and it is a promising means for aberration measurement. However, how to optimize its parameters to achieve the...
For more than 15 years, Imagine Optic have developed Extreme Ultra Violet (EUV) and X-ray Hartmann wavefront sensors for metrology and imaging applications. These sensors are compatible with a wide range of X-ray sources: from synchrotrons, Free Elec...
Background: Hartmann’s procedure remains a commonly performed emergency operation for obstructive or perforated left-sided colorectal disease, yet bowel continuity is restored in only 25–40% of patients, and Hartmann’s reversal carr...
Shack-Hartmann wavefront sensor plays a key role in adaptive optics (AO) systems, which detect the aberrant wavefront by an array of micro-lenslets across the aperture pupil. However, some sub-apertures would be a lack of light induced by the imperfe...
Due to the influence of atmospheric turbulence, the detector, and background noise, the subaperture image of an extended scene Shack–Hartmann wavefront sensor will have a low signal-to-noise ratio, which will introduce errors to the offset esti...
With the successful application of the Shack–Hartmann wavefront sensor in measuring aberrations of the human eye, researchers found that, when the aberration is large, the local wavefront distortion is large, and it causes the spot correspondin...
Hartmann–Shack wavefront sensors (HSWSs) are widely used for ocular aberration measurements. However, image artifacts introduced during acquisition, such as blinks and undesired reflections, can impair spot detection and lead to inaccurate wave...
Background/Objectives: Hartmann’s procedure is commonly employed to manage complications of acute sigmoid diverticulitis, such as perforation or abscess formation. However, determining the optimal timing for colostomy reversal remains a topic o...
The restoration of bowel continuity following Hartmann’s Procedure (HP) has been reported hitherto with high morbidity and mortality rates. No clear guidelines exist about timing in Hartmann’s Reversal (HR), the literature data being conf...
Shack–Hartmann wavefront sensors (SHWFSs) are crucial for detecting distortions in adaptive optics systems, but the accuracy of wavefront reconstruction is often hampered by low guide star brightness or strong atmospheric turbulence. This study...
Background/Objectives: Intraoperative aberrometry has gained clinical relevance in correcting aberrations during cataract and corneal refractive surgeries. As wavefront aberrations are typically measured with patients seated, while surgeries are perf...
The Hartman wavefront sensor can be used for X-ray phase imaging with high angular resolution. The Hartmann sensor is able to retrieve both the phase and absorption from a single acquisition. The system calculates the shift in a series of apertures i...
This paper details the development of a varifocal Shack–Hartmann wavefront sensor (SHWFS) featuring an innovative mechanism for dynamic microlens array adaptation. The core of this advancement is a closed-loop iterative algorithm designed to op...
Introduction: The objective of this study was to analyze and compare the outcomes of two surgical techniques in the emergency management of obstructed colorectal carcinoma. Methods: This is a retrospective analysis of patients’ data from a tert...
This paper presents a real-time implementation of a hybrid connected component labeling method for processing the Shack–Hartmann wavefront sensor’s images for an adaptive optics (AO) system. The output image of a wavefront sensor is an im...
A cross-correlation algorithm to obtain the sub-aperture shifts that occur is a crucial aspect of scene-based SHWS (Shack–Hartmann wavefront sensing). However, when the sub-image is partially absent within the atmosphere, the traditional cross-...
Atmospheric turbulence is an inevitable source of wavefront distortion in all fields of long range laser propagation and sensing. However, the distorting effects of turbulence can be corrected using wavefront sensors contained in adaptive optics syst...
We present a computational proof of concept, inspired by a recent patent developed by Nikolai Suchkov and Siegfried Wahl (European Patent Office EP4179957A1), of a virtual multi-eccentric Hartmann–Shack (HS) aberrometer for simultaneous measure...
Research has shown that longitudinal chromatic aberration (LCA) of the human eye is generated across all of the eye’s optical surfaces. However, it may not be necessary to measure the LCA from the first surface of the cornea to the retina, as i...
The Shack–Hartmann wavefront sensor (SHWFS) is widely utilized for ocular aberration measurement. However, large ocular aberrations caused by individual differences can easily make the spot move out of the range of the corresponding sub-apertur...
The hybrid model for analyzing distortions of a laser beam passed through a moderately scattering medium with the number of scattering events up to 10 is developed and investigated. The model implemented the Monte Carlo technique to simulate the beam...
We present a fast and reconfigurable architecture for Shack–Hartmann wavefront sensing implemented on FPGA devices using a stream-based center of gravity to measure the spot displacements. By calculating the center of gravity around each incomi...
The multi-beam array stitching test system (MASTS) based on the Hartmann principle is employed to measure the aberrations in large-aperture optical systems. As each small-aperture and ideal parallel beam traverses the optical system, it is converged...
The present paper provides a brief overview of the existing methods for energy separation and an analysis of the possibility of the practical application of the Hartmann–Sprenger effect to provide quasi-isothermal pressure reduction of natural...
This research focuses on the development of a quasi-isothermal pressure regulator based on the principle of flow mixing after energy separation. Currently, no established methods exist for designing pressure reduction devices that utilize energy sepa...
Accurate measurement and characterization of high-power laser beams is essential for free-space optical communication, wireless energy transmission, atmospheric turbulence compensation, laser cutting, and space debris removal. Shack–Hartmann wa...
High-quality in-depth imaging of three-dimensional samples remains a major challenge in modern microscopy. Selective plane illumination microscopy (SPIM) is a widely used technique that enables imaging of living tissues with subcellular resolution. H...
Scleral lenses (SLs) are increasingly incorporating complex optical designs, including front surface eccentricity (FSE) optimisation and wavefront-guided (WFG) corrections, to address residual higher-order aberrations (HOAs) in eyes with irregular co...
1 January 2014
Wolfgang Fleischhacker und Hartmann Hinterhuber haben mit dem «Lehrbuch Psychiatrie» eine ebenso umfassende wie fesselnde Übersicht über das Fachgebiet Psychiatrie vorgelegt [...]
An array of compound refractive X-ray lenses (CRL) with 20 × 20 lenslets, a focal distance of 20cm and a visibility of 0.93 is presented. It can be used as a Shack-Hartmann sensor for hard X-rays (SHARX) for wavefront sensing and permits for tr...
The precise estimation of fluid motion is critical across various fields, including aerodynamics, hydrodynamics, and industrial fluid mechanics. However, refraction at complex interfaces in the light path can cause image deterioration and lead to sev...
This work presents a numerical simulation of a Hartmann-Shack wavefront sensor (WFS) that assesses the impact of integrated electronic circuitry on the sensor performance, by evaluating a full detection chain encompassing wavefront sampling, photodet...
Background: The surgical management of remnant rectosigmoid after subtotal colectomy with end ileostomy for acute severe ulcerative colitis remains controversial with respect to the need to perform sigmoidostomy or Hartmann’s pouch. The aim of this r...
Background and Clinical Significance: Extensive rectal ischemia is exceptionally rare due to the rectum’s robust vascular network, with segmental ischemia being more common. Case Presentation: We report the case of a 69-year-old female who pres...
Background and Objectives: Complicated left-sided colonic diverticulitis is one of the important causes of hospital admissions and emergency surgery in industrialized societies and requires serious clinical decision-making processes for patient manag...
Free Space Optical Communication (FSOC) is a wireless communication method that utilizes laser beams for high speed and secure data transmission. Its performance is affected by various factors, among which atmospheric turbulence causes random fluctua...
The effect of the direction of external horizontal magnetic fields on the linear stability of natural convection of liquid metal in an infinitely long vertical rectangular enclosure is numerically studied. A vertical side wall is heated and the oppos...
Medieval literature often seems to be a remote, irrelevant, incomprehensible world of narrative texts lost in heroic, religious, or courtly themes, limited to stories about King Arthur, courtly lovers, military heroes, and religious martyrs, saints,...
The Hartmann wavefront sensor is able to measure, separately and in absolute, the real δ and imaginary part β of the X-ray refractive index. While combined with tomographic setup, the Hartman sensor opens many interesting opportunities beh...
This paper presents the results of a study that was largely initiated to describe a genus and species of weevil damaging macadamia fruits in plantations in New South Wales and Queensland, Australia. This taxon is described as Kuschelorhynchus macadam...
Seismic wave analysis is crucial for identifying subsurface formations and geological hazards. In this study, a seismic wave laser remote sensing system based on a Shack–Hartmann wavefront sensor was established by exploiting its high spatial r...
Recent scholarship, particularly Steve Odin’s, has drawn attention to the originality of D. T. Suzuki’s conception of the unconscious. Building on this discussion, this article investigates the historical formation and conceptual transfor...
Ti-35Nb-xSn (x = 0, 4, 6 wt.%) alloys were consolidated by Electrical Resistance Sintering (ERS) at 11 and 12 kA to address the elastic-modulus mismatch and ion-release limitations of Ti-6Al-4V, exploiting the β-stabilizing effect of Nb and oxid...
We present the application of single-shot multicontrast X-ray imaging with an inverted Hartmann mask to the time-resolved in situ visualization of chemical reaction products. The real-time monitoring of an illustrative chemical reaction indicated the...
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