Login with Facebook

Principle of Optical coherence tomography (OCT)

Optical coherence tomography is a non-destructive interferometric process allowing cross-sectional images of biological tissue to be produced with a resolution of the order of a micrometer. OCT uses a low coherence light beam, usually emitted by a superluminescent diode. Similarly to what sonar does with the backdrops (acoustically), due to the computerized analysis of the light reflected from the tissues under examination, it is possible to reconstruct the structure in two or three dimensions. The OCT can return images in color or in black and white that is with the grayscale, both with great details.

We propose to illustrate the principle. The principle of ultrasound has been applied to optics using optical coherence tomography. Will this interference method soon provide the means to examine any suspect tissue in real-time.

How to examine in its thickness an inaccessible biological tissue, such as the retina? One solution is to take an image of it by optical coherence tomography or OCT. It is invented fifteen years ago by James Fujimoto, a physicist at the Massachusetts Institute of Technology. The OCT (Optical coherence tomography) is a kind of optical ultrasound; the ultrasound has been replaced by infrared light. 

It makes it possible to view the structures with a resolution of up to a micrometer, and this in real-time, in situ, and without contact without sampling or preparation. Today in common use in ophthalmology, the OCT is promised for a whole series of applications in dermatology, gynecology, cardiology, etc.

During clinical trials, these new applications are the result of recent technical research and the development of several variants. After having explained the principle of optical coherence tomography, we will present its most advanced applications, including open field optical coherence tomography.

Optical coherence tomography compares to ultrasound for the most part. Recall what the latter consists of a probe in contact with the patient's skin emit ultrasound, which is then more or less absorbed or reflected depending on the density of the biological tissue encountered. A sensor measures the reflected ultrasonic signals. The return times and the variations in the intensity of the echoes then make it possible to reconstruct an image of the biological tissue up to several centimeters deep and with a resolution of the order of a millimeter.

In optical coherence tomography, ultrasound is replaced by light, and the reconstructed image depends on the absorption and reflection of this light by biological tissues. In principle, substitution has several advantages, like, given the short wavelengths of light, the details of the tissues are revealed in width (the direction perpendicular to the propagation of the waves). With the resolution of optical microscopy, 1,000 times that of imaging by ultrasound. As for the resolution in-depth, it depends on the brevity of the light pulses used, with the ultra-short pulses of a femtosecond laser (a femtosecond is 10–15 seconds). 

It could determine the depth of an area from which it comes from an optical echo with a micrometric resolution. In fact, in ten femtoseconds, the light travels only two micrometers in a tissue! Tissue details are revealed in width (the direction perpendicular to the wave propagation) with the resolution of optical microscopy, 1,000 times that of ultrasound imaging. As for the resolution in-depth, it depends on the brevity of the light pulses used. 

With the ultra-short pulses of a femtosecond laser (a femtosecond is 10–15 seconds), one could, in principle, determine the depth of an area from which comes from an optical echo with a micrometric resolution. In fact, in ten femtoseconds, the light travels only two micrometers in tissue. Tissue details are revealed in width (the direction perpendicular to the wave propagation) with the resolution of optical microscopy, 1,000 times that of ultrasound imaging. 

As for the resolution in-depth, it depends on the brevity of the light pulses used with the ultra-short pulses of a femtosecond laser (a femtosecond is 10–15 seconds). One could, in principle, determine the depth of an area from which comes from an optical echo with a micrometric resolution. In fact, in ten femtoseconds, the light travels only two micrometers in tissue. With the ultra-short pulses of a femtosecond laser (a femtosecond is 10–15 seconds), we could, in principle, determine the depth of an area from which an optical echo comes with a micrometric resolution. 

In fact, in ten femtoseconds, the light travels only two micrometers in a tissue! With the ultra-short pulses of a femtosecond laser (a femtosecond is 10–15 seconds), we could, in principle, determine the depth of an area from which an optical echo comes with a micrometric resolution. In fact, in ten femtoseconds, the light travels only two micrometers in tissue.

However, this promising principle of "optical ultrasound" cannot be put into practice directly because no light detector is fast enough to measure propagation times (back and forth), which are measured in femtoseconds.

- In order to obtain optical images of biological tissues in the form of a section or tomography, it is first necessary to measure its internal structures. In OCT, the first step to obtaining these images is to measure the axial distance inside the tissue. When a beam of light is directed inside the eye, it is reflected in the level of the interfaces between the different tissues and diffuses in a different way from tissues that have different optical properties. The distances and dimensions of the different ocular structures can be determined by measuring the time of delay of the echo of light that is reflected or backscattered by the different structures at vary the axial distance.

- It is defined with ΔT =V/z the temporal resolution associated with the instrument a measure the delay of the light echo; Δz is the distance covered by the echo. While v is the speed of propagation of the echo in the fabric, therefore for typical values ​​of Δz of 5 μm, with v equal to 3×10 8 m/sOptical coherence tomography (OCT), there will be temporal resolutions of about 15 femtoseconds.

- The only way to detect such fast signals is to use tools of detection that exploit the principle of interferometry.

Author: Vicki Lezama


Comments

Need a custom
essay?

We will write it for you.
Order now

Free Essay Examples

Free essays:

An insight into the error-correction models
All you need to know about management discipline?
A historical overview of Financial Crises
All you need to know about reaction kinetics?
Basics the Game Theory in Cryptoeconomics
Business innovation ideas for making money
Biosensors for cancer diagnosis
Business Analysis: Pricing strategies and Demand Curve
Contracting with Moral Hazard and Adverse Selection
Conflict management in an organization
Can social media help overcome the problem of illiteracy?
Cultural heritage of indigenous people.
Digital Illiteracy
Determinants of business cycles fluctuations
Determinants of Unemployment and Inflation
Different tissues of the body
Economic Analysis of Market Structure
Expected Utility
Everything you need to know about workplace diversity
Efficiency and Market Equilibrium
Factors Affecting Purchasing Behavior
Financial Statement Analysis
Factors Influencing Interest and Exchange Rates
Fiscal and Monetary Policies in Response to 2008/2009
Game theory in microeconomics
Globalization: definition, causes, social impact and risks
Gene expression: what it is and why it is important
Global environmental issues
How to conduct economic research?
How to define the Enterprise Value
How cancer is developed - Cancer biology
How can financial illiteracy harm you?
Illiteracy in the USA
Importance and seven principles of quality management
Intermediaries and Government in Financial Crisis
Introduction to Econometric Application
Journalism: What is News?
Journalism: Broadcast media and Television Presenters
Journalism: Sources of News
Journalism and Law
Key Determinants of National Income
Key Factors That Affect Pricing Decisions
Kinetic models in biology and Related fields
Know about the different forms of traditional African dances
Latest technology trends
Latest dance trends
Methods of labeling of nucleic acid that enable their detection
Macroeconomics: International Economic Issues
Neuromuscular disorders
National Economies, Fluctuation, and Responses to Fluctuations
Neurotransmitters: what they are and different types
Nanomedicines to target tumors
Organizational motivation and its effects
Overcoming Hiring Challenges for Nonprofit Organization
Protection of cultural heritage in times of war and peace.
Principles of Corporate Governance.
Risk Sharing in Insurance and Asset Markets
Risk and the value of information
Reverse discrimination.
Role of media in wartime.
Segregation in the US.
Stages of the Consumer Decision-Making Process
Structure and function of blood vessels
Skills in Journalism: Effective Interview
Theories of Public Policy
The Economics of Uncertainty – Introduction
The different medical imaging techniques
Tips for labeling medical devices- Medical Entrepreneurship
Understanding Auctions and Auction Theory: Part 2
Understanding Auctions and Auction Theory: Part 1
Use of Machine Learning in Econometrics
Understanding Public Policy
Various theoretical perspectives of sociology
Virtual reality, what it is and how it works
What is Immune System and Immunotherapy?
What are the methods of valuation of companies?
4 Facts about Origin of Mathematics!
5 techniques to create an animation
10 emerging technologies according to World Economic Forum
10 strategies to maximize corporate profits
3d Model Of Building
6 Medical Technologies that revolutionized the healthcare in 2020
All you need to know about the ACA Code of ethics
Architecture and Democracy: An Introduction
Architecture and Democracy: Democratic Values
Architecture and Democracy: Democratic Procedures
All You Need to Know About a Synthesis Essay
An essential guide to understanding Film Theory
Application of Artificial Intelligence in Cyber Security
Applications of electrical engineering
Augmented reality: what it is, how it works, examples
Advantages And Disadvantages Of Social Networking
All you need to know about Cryptography
Applications of astrophysical science
All you need to know about architecture engineering
Applications of geological engineering
Artificial intelligence and medicine: an increasingly close relationship
An insight into Computational Biology
ACA code of conduct
A Rose for Emily
Applications of Mathematics in daily life
Architecture mistakes to avoid
All you need to know about Toxicology
All you need to know about Holistic Medicine
All you need to know about linguistics
An introduction to Linguistics and its subfields
All you need to know about Anxiety disorder
All you need to know about Drones
A Brief Insight into Political Science
Assumptions related to feminism
All you need to know about Byzantine emperors
All you need to know about labour economics
An insight into xenobots -the first-ever robots
An ultimate guide about Biomaterials
A Comprehensive Introduction to the Mona Lisa
Analysis methods of Transport through biological membranes
An ultimate guide about biochemical reactions
Analysis of brain signals
Artificial Gene Synthesis
Application to synthetic biology of CAD methods
All you need to know about metabolic pathways
Applications of BIOMEMS
All you need to know about the epidemiology
Asian vs. western leadership styles
All you need to know about Smart prosthesis
Analysis of Economy: Output of Goods and Services (GNP), and GDP on Economic success
A Guide to Pricing Strategies
An Overview Of Economic Studies
Analysis of Fiscal and Monetary Policies
Analysis of Business Cycles
Analysis of Consumption and Investment
A Look into Regression Analysis
Analysis of Household's Consumption and Savings Behavior
All you need to know about Capital Budgeting
All you need to know about risk management
Art looted in wartime.
Appropriate use of Data in Economics
All you need to know about reaction kinetics?
A historical overview of Financial Crises
All you need to know about management discipline?
An insight into the error-correction models
How to Write a Personal Essay
Housing Needs in America
How to Write a Description Essay
How to Create an Excellent Scholarship Essay?
How to write a cause and effect essay
How to Hire the Best Essay Writing Service Provider?
How to Write a College Application Essay?
How to get the most out of your English lectures
How to write Expository Essay
How to succeed in your psychology class?
How to Write an Academic Essay in the Shortest Time?
History of Journalism
How Different Sectors are Using Artificial intelligence (AI)
How to write an informative essay
How to deliver persuasive essays?
How to Give a Convincing Presentation
How to write an essay on leadership?
Historical Art Still Around Today
Humanoid robot: what it is, how it works and price
History of Chemistry
Healthcare Advanced Computer Power: Robotics, Medical Imaging, and More
Healthcare AI: Game Changers for Medical Decision-Making and Remote Patient Monitoring
How to understand different types of English
How to Cope with Chronic Pain
How African American choreographers and dancers have influenced American dance
How mobile robot can do in logistics or in production
How To Become a Successful Entrepreneur
History of the Philosophy of Feminism
How is the climate changing?
How to Track Your Content Marketing ROI
How to Gun control In the USA?
Historical and contemporary role of labour in the modern world
How breast cancers are classified?
How the cells of our body communicate?
How the Lymphatic System Works?
How Digestive System Works
How to complete your capstone projects effectively?
How to write a research project
Healthcare technologies that help patients with better self-management
How to choose the topic of the senior capstone project
How to make your business survive at economic crisis
How can immigrants blend in the American society?
How does the economics of war affect society?
Hate speech on social media.
How to Build an Economic Model
How to start a healthcare startup?
How can financial illiteracy harm you?
How cancer is developed - Cancer biology
How to define the Enterprise Value
How to conduct economic research?
Introduction to Urban Studies
Importance of dance in education
InMoov: how to build an open source humanoid robot
Importance of KYC verification to making the Blockchain secure
Importance of Rhythm
Importance of dance student evaluation
I/O control methods -types and explanations
Identity theft: what to do?
Introduction to Utilitarianism
Importance of 3d Modelling in Architecture
Importance of online journalism
Image processing in medical diagnosis
Introduction to USA Politics
Introduction to Comparative Politics
International Relations as a Major in Political Science
Importance of modern trade policy
Introduction to Journalism
Introduction to Writing a TV Script
Introduction of Microfabrication techniques
Introduction to Microeconomics
Interaction of Consumer and Firm Choices in Markets
Importance of corporate sustainability
Issues in International Monetary Macroeconomics
Introduction to Statistics and Data for Economics
Introduction to Data and Probability for Economics
Introduction to the Game Theory
Introduction to Econometrics
Introduction to Economic Information
Introduction to Market Equilibrium
Introduction to Economic Models and Application
Introduction to Empirical Research
Introduction to Econometric Data
Importance of Critical Thinking, Principles, and Goals
Introduction to Identification and Causal inferences
Introduction to Econometric Application
Intermediaries and Government in Financial Crisis
Importance and seven principles of quality management
Illiteracy in the USA
The Looming Energy Crisis in America
Top benefits of performance-based engineering
The More Languages You Know, The More Times You Are a Man
Things to consider while writing an Argumentative Essay
Top Ways to Improve Your Academic Writing Skills
Tips to Excel in Creative Writing
The origins of films in the early 19th century
Top career options in Architecture
The Elevator Pitch
Top finance trends 2020
The basic Structure and functionality of robots
The Way to Success
The election system of the President in the United States of America
Two-party System in United States of America
Top trends in urban design
The history and theory of African American filmmaking
Top benefits of creative writing
Tinnitus Guide: Common Symptoms and Treatment Options
The language of dance
The digital image processing management
Top famous politicians of the World
Top methods of political science!
The history of the feminist movement
The blood flow in cardiovascular system - Biofluid Mechanics
The best of Leonardo Da Vinci
The Structure and Function of Macromolecules
The structure of cell: a research on the bricks of the human body!
Tissue and organ construction: Adhesion and recognition between cells
The kinetics of the transformation processes
The Modeling of Biological Systems
Tips for writing a great thesis statement
The Defense mechanisms against infections
The impact of the technological innovations in medicine
Top journalism trends to know about
The relation between mass media & politics
Theranostics: Diagnosis and Care through Nanoparticles
The practical Applications of X-rays
The applications of Ultrasound in medicine
Transfer mechanisms of genetic information in Bacteria
The regulation of cellular metabolism in the diagnosis
The Principles of MRI Contrast agents
The technical basis of optical coherence imaging
The New Media: Emerging Trends
The Structure of Interest Rates and the Yield Curve
Technological perspectives and reflections of neural engineering
Types of bioreactors and their applications
The Role of Government Policy in Improving Economic Outcomes
Types of corporate responsibility
The Role of IMF in International Monetary Macroeconomics
Tools for investment decision making
The concept of Organizational Culture and its applications
The Conduct of Monetary and Fiscal Policy
The Basics of Financial Accelerator Models
Tips for labeling medical devices- Medical Entrepreneurship
The different medical imaging techniques
The Economics of Uncertainty – Introduction
Theories of Public Policy
What is a Definition Essay?
What are diagnostic essays?
What is the relation between art structural engineering?
What is a Narrative Essay
What are robotics and intelligence systems?
What are the benefits of studying health sciences?
What is artificial intelligence and why it matters?
What is comparative Literature?
Why study neuroscience
What is Wi-Fi and how does it works
What is French history famous for?
What are Humanistic Studies?
What is covered in Biophysics?
What is modern journalism?
What is Virtualization? Benefits & Applications
What are modern public relations?
What is plasma physics?
What is teacher preparation?
What is rapid prototyping for 3D printing?
What is contemporary European Politics?
Why should you learn American Ballet?
What is engineering physics?
What is the purpose of African American Literature?
Ways to learn the Rhythm
What is digital art used for?
What are Enzymes and how do they work
Who is the father of political science?
Why Study Political Science - Job?
What is the Philosophy of Feminism?
What is a quantum computer?
Ways B2B Startups Streamline Their Conversion Strategies
Why do biomedical signals need processing?
What are the long term effects of climate change?
Why study labour relations
What is Holoprosencephaly?
What is antisocial disorder?
What are the important principles of evolution?
What is the cytoplasm and its function?
What is biopolymers?
What Makes a Good Leader
Women empowerment in modern generation
What is the history of political thought?
What is Gene recombination
What is synthetic biology
What is business cost analysis?
What is Inflation
What are the consequences of unemployment?
What is lithotripsy and its types?
What is transition elastography?
What is the purpose of deep brain stimulation?
What is a Brain-Computer Interface (BCI)
What is neuroethics?
What is Market and Supply and Demand
What is optogenetics?
What are the techniques to record brain activity?
What happens if the interest rate increases?
What is immunotherapy?
What is the economic role of the financial market?
What are the factors behind illegal immigration?
What is the lymphocyte activation?
What is financial market and its types?
What is the structure of financial markets?
What are the methods of measuring business performance?
What is the Credit market?
What is business ethics and code of ethics
What are the Causes of financial instability?
What is MBA with Concentrations
What is regenerative medicine?
What is Population ecology?
What is Microfinance: evolution, and practices?
What is biotechnology and its applications?
What are Workplace diversity and its benefits?
What is the difference between a leader and a manager?
What Is Branding and best branding Business strategies?
Why are microelectronics important?
What are biologic drugs.
What is the Foreign Exchange market?
What is the role of scientific research in times of crisis?
What are the risks of international trade?
What is financial management?
What is gene therapy?
What is education economics?
What is regression analysis, and why should you use it?
What Is Technology Marketing And How Should It Work?
What is Management Accounting
What are the methods of valuation of companies?
What is Immune System and Immunotherapy?