Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons

¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons

Protons in identical electronic environments within a molecule are chemically equivalent and have the same chemical shift. The replacement test is a useful tool to identify chemical equivalence and predict NMR spectra. A substituent replaces each of the protons being examined and the resulting molecules are compared. If the same molecule is obtained, the protons are equivalent or homotopic. Replacement of any hydrogens in ethane by chlorine yields chloroethane because all six protons are...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Baseline Mismatch Negativity Amplitude Predicts Direction and Magnitude of Ketamine Effect in Healthy Volunteers: A Disordinal Effect.

Biological psychiatry·2026

Same author

The occurrence of and risk factors for depressive symptomatology in myocarditis survivors: a cross-sectional survey-based study using machine learning.

Frontiers in psychiatry·2025

Same author

Synaptic proteins in neuron-derived extracellular vesicles as biomarkers for Alzheimer's disease: novel methodology and clinical proof of concept.

Extracellular vesicles and circulating nucleic acids·2023

Same author

Electrophysiological biomarkers and age characterize phenotypic heterogeneity among individuals with major depressive disorder.

Frontiers in human neuroscience·2023

Same author

Digital phenotyping approaches and mobile devices enhance CNS biopharmaceutical research and development.

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology·2018

Same author

Replicable in vivo physiological and behavioral phenotypes of the <i>Shank3B</i> null mutant mouse model of autism.

Molecular autism·2017

Search research articles

Related Experiment Video

Updated: Jul 2, 2026

Detection of Architectural Distortion in Prior Mammograms via Analysis of Oriented Patterns

Detection of Architectural Distortion in Prior Mammograms via Analysis of Oriented Patterns

Published on: August 30, 2013

Generalized method for sorting Shack-Hartmann spot patterns using local similarity.

Daniel G Smith¹, John E Greivenkamp

¹Nikon Research Corporation of America, 12490 North Rancho Vistoso Boulevard, Suite 130, Tucson, Arizona 85742, USA.

|September 2, 2008

Summary

A new spot sorting method improves Shack-Hartmann wavefront sensor performance by robustly associating lenslet spots. This technique enhances sensitivity and dynamic range, applicable to various lenslet array geometries.

More Related Videos

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments

Published on: March 1, 2022

Related Experiment Videos

Last Updated: Jul 2, 2026

Detection of Architectural Distortion in Prior Mammograms via Analysis of Oriented Patterns

Detection of Architectural Distortion in Prior Mammograms via Analysis of Oriented Patterns

Published on: August 30, 2013

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments

Published on: March 1, 2022

Area of Science:

Optical Engineering
Wavefront Sensing
Metrology

Background:

Shack-Hartmann wavefront sensors (SHWS) offer enhanced sensitivity and dynamic range when lenslet spots shift beyond one radius.
This increased dynamic range poses a challenge in accurately associating shifted spots with their original subapertures.
Robust spot-to-subaperture mapping is crucial for reliable wavefront reconstruction in SHWS.

Purpose of the Study:

To develop a simple and robust algorithm for sorting Shack-Hartmann spots.
To enable accurate subaperture assignment for shifted spots in SHWS.
To demonstrate the algorithm's applicability to various lenslet array geometries, including hexagonal and square lattices.

Main Methods:

A novel spot sorting algorithm is presented that leverages local spot position distortions.
The algorithm effectively 'unwraps' the spot pattern, enabling correct association with subapertures.
The method's performance is evaluated across different lenslet array configurations.

Main Results:

The developed algorithm provides accurate and robust spot sorting, even with significant spot displacement.
Hexagonal lenslet arrays are shown to be more efficient than square arrays for this application.
The method is demonstrated to be effective for any two-dimensional lattice geometry.

Conclusions:

The proposed spot sorting algorithm successfully addresses the challenge of associating shifted spots in SHWS.
This technique enhances the practical utility of SHWS with extended dynamic range.
The findings highlight the advantages of hexagonal arrays and provide a versatile solution for wavefront sensing.