The document discusses lasers, including their principle, construction, types, and uses. It begins by explaining that a laser works by stimulating electrons to produce coherent and monochromatic photons through population inversion. The key components of a laser are a pump source to cause excitation, a gain medium such as gas or solid, and an optical resonator with mirrors. Common medical lasers described include CO2, Nd:YAG, diode, and excimer lasers used for procedures like photocoagulation, photodisruption, and photoablation. Industrial and scientific uses as well as laser safety are also covered at a high level.
Polarization and it's application in OphthalmologyRaju Kaiti
Polarization, types of polarization, mechanisms to produce polarization, Applications of polarization, precautions with polarizing sunglasses, ophthalmic uses of polarization
Polarization and it's application in OphthalmologyRaju Kaiti
Polarization, types of polarization, mechanisms to produce polarization, Applications of polarization, precautions with polarizing sunglasses, ophthalmic uses of polarization
Lasers in ophthalmology - Dr. Parag Apteparag apte
A full presentation of one hour of all types of lasers in ophthalmology for under graduates and post graduates after going through all the uploaded slides till today. This includes laser photocoagulation, laser iridotomy, and laser capsulotomy in detail
Lasers in ophthalmology - Dr. Parag Apteparag apte
A full presentation of one hour of all types of lasers in ophthalmology for under graduates and post graduates after going through all the uploaded slides till today. This includes laser photocoagulation, laser iridotomy, and laser capsulotomy in detail
Laser characteristics as applied to medicine and biologykaroline Enoch
Laser” is an acronym for light amplification by stimulated emission of radiation. A laser is created when the electrons in atoms in special glasses, crystals, or gases absorb energy from an electrical current or another laser and become “excited.”Characteristics ,working ,types and application of lasers exclusively in medicine and biology.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Similar to Laser and it's clinical application (20)
magnification, It's definition, types, clinical uses, Uses in Optical instruments like microscopes, telescopes, Uses in Optical instruments like direct Ophthalmoscopes, indirect ophthalmoscopes and slit lamps, In low vision
Color vision physiology, defects and different testing ProceduresRaju Kaiti
Color vision Physiology, Different types of Color vision defects, different testing procedures, trichromatic theory, color opponent theory, inheritance of color vision defect, management of color vision defect
Pediatric Ophthalmic dispensing in different visual problemsRaju Kaiti
Pediatric dispensing, introduction, different from adult dispensing, frame selection, lens selection, special case fitting, Do's and Dont's, Measurements, Down's syndrome, albinism, aphakia, strabismus, syndromes
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
2. LASER (Principle, Nature & Application)
• LASER – acronym for
Light Amplification by Stimulated Emission of Radiation
• LASER coined – Gordon Gould
• Albert Einstein (1917) – explained basic physical process –
Stimulated Emission
• Theoddore Maiman (1960) – Built first LASER
3.
4. Light – Photon (wave Packets)
Energy (E) = h * f
where, H is planck’s constant and f is the frequency
-Atom – nucleus at the center and electrons revolving round
round the specific orbits along with other empty orbits that
electron could potentially occupy
- Each orbit has specific energy level, so to jump from one
orbit to another an electron must gain or loose energy
5. Every atom always tends to remain in lowest Energy Level (ground
state)
Get energy- Excited state – Ground state by losing energy in the
form of photon
7. POPULATION INVERSION
• Precondition of laser action
• Electrons will normally reside
in lower available energy state
• Absorption lead to electrons
in the excited state
• No significant collection of
electrons in higher states due
to spontaneous emission
8. • Life time of typical excited =10-8
sec
• Material is induced to have majority of atoms
in the higher excited state i.e N2>N1
9. General construction of laser
• Population inversion is
necessary
• 3 principal parts
Pump source
Gain medium
Optical resonator
10. Pump source
• Can be
Chemical reaction
Electric discharge
Light from another laser
• Depend upon gain medium
• Chain of stimulation emission occur
• Excites lasing medium into population inversion
11. Gain Medium
• Solid: Crystall & glass
• Liquid :Organic solvent, Glycol
• Gases :CO2, Ar, Kr. He-Ne
• Semiconductor
12. Optical resonator
• Two mirrors are placed at each end of the cavity –
- totally reflecting (100%)
- Partially (99%)
- Coherent light escape from the cavity return back after
reflection and produce more stimulated emission.
• leads to Amplification
Small amount of light pass through partially reflecting mirror
-LASER
15. Charecteristics of laser light
1. Coherence : as the radiation is produced by the
single stimulus they have same phase difference,
importance in holography
2. Monochromatic :as the light of laser comes from
the same atom transition it has a single wavelength
,depends upon the type of material
16. • Collimated :because of bouncing of radiations between the
mirrors ,becomes perpendicular to the mirror and while
emerging from the cavity are collimated or parallel and not
much spreaded.
• Directional
21. Types of Laser
• According to their sources:
• Gas Lasers
• Crystal Lasers
• Semiconductors Lasers
• Liquid Lasers
• According to the nature of emission:
• Continuous Wave
• Pulsed Laser
• According to their wavelength:
• Visible Region
• Infrared Region
• Ultraviolet Region
24. PHOTORADIATION/ PhotodynamicsPHOTORADIATION/ Photodynamics
• Occurs when tissue temperature is raised from 37-380
c
• To treat tumors
• Uses photosensitizing agent
• Photosensitizing material causes light induced reaction
in molecule that doesn’t absorb light
25. PHOTOCOAGULATIONPHOTOCOAGULATION
•Occurs when tissue temperature is raised from
37-650
c
•Causes thermal damage that causes
denaturation of protein
•4 changes occur
– Scar- cause tissue to bind or adhere
– Tissue atrophy
– Collagen and smooth muscle contraction
– Blockage of blood vessels
26. • Ocular examples of photocoagulation
– Pan retinal photocoagulation
– Trabeculoplasty
– Peripheral iridectomy
– t/t of choroidal neovascular membrane
– Sealing of holes in RD
27.
28. PhotovaporisationPhotovaporisation
• Occurs when tissue temperature is raised from 37-1000
c
• Target tissue is converted to water vapour and smoke
• Treat malignant tumor of choroid or retina
29. PHOTODISRUPTIONPHOTODISRUPTION
• Occurs when tissue
temperature is raised from
37-20,0000
c
• Cause transient shock wave
which cause tissue damage
due to mechanical stress
• Ocular example
– Nd- YAG capsulotomy
31. TYPES
A. SOLID
1)Ruby laser
•1st
type of laser
•Chromium ion is active ingredient
•As pulsed laser, red light=694.3nm
•3 energy levels
2) Nd-YAG
•4 energy levels
•Neodymium added to YAG
•1064nm,high powers
32. 3) Semiconductor lasers
• Diode laser
• Used in data processing and fibre optics
• Gallium arsenide-infrared fine for fibres
•
B. GAS LASERS:
1)He-Ne laser:
• Widely used
• 5 parts He and 1 part Ne pressure of 1 mm Hg
• Common and inexpensive
• 623nm, 543.5nm and 1523nm
33. 2) CO2 laser
• Continuous output
• IR frequencies
• N2 as pumping gas
• Cutting and Welding
3) Argon lasers
• Continuous output in 25 different wavelengths
• Much higher than He-Ne laser
34. C)Dye laser: mostly liquid laser
Widely used dye rhodamine 6G
Often combines with michelson interferometer
D)Excimer laser: excited dimer
Active medium is the diatomic molecule
In submarines
LASIK
E)free electron laser:
Wide range of frequencies
Types contd…..
35.
36. Laser in ophthalmic Use
• Nd- YAG
• Semiconductor/Diode
• Argon
• Krypton
• Excimer
40. Excimer laser
• Excited dimer laser
• Xenon+Halogen-------Xe(halogen)8
• Emit photons of 193 nm under high pressure.
• Principle: Photoablation
• Used for
Photorefractive keratectomy
LASIK
Band keratopathies.
41. DIODE LASERS
• Use semi conductors
• Used in ocular oncology like
melanoma
retinoblastoma.
42. Three Basic Ways for Photon and Atom Interaction
• Absorption – Electron can absorb passing photon
to jump into higher energy level
• Spontaneous emission – Electron in high energy state
spontaneously drop down to lower energy state and create
photon.
E= energy difference betwn two orbits
43. Stimuated Emission-
Passing photon at the vicinity of atom stimulates the electron to drop
and emit photon
Excited atom is struck by photon of same
energy as the photon to be emitted
Frequency of stimulating photon and emitted photon is same along with
phase – Two Photons are coherent
44. How LASER - Produced
• Gases, liquid and solids – working materials
• Krypton and Argon – LASER for LASER surgery
• Working materials enclosed in a cylindrical tube – LASER Tube
• Most of the electrons are in their ground state – natural condition
• Few at excited state – spontaneous emission – photon – stimulated
emission as it pass thru other excited atom
45. But to sustain number of stimulated emission, the electrons in high energy state
must exceed electrons in low energy state – Population Inversion
- the gas in laser tube is pumped by electric discharge/powerful light
- Maintain the population inversion
- Few electrons – spontaneous emission – photons – Stimulate high energy level
electron- Stimulated emission – coherent photon
- Chain Rxn – two mirrors are placed at each end of the cavity –
- totally reflecting (100%)
- Partially (99%)
- Coherent light escape from the cavity return back after reflection and produce
more stimulated emission.
- Small amount of light pass thru partially reflecting mirror -LASER
46. Some LASERS
• Helium neon LASER – Red 632.8 nm
• Krypton – Red 647.1 nm
• Argon – Blue and blue green – 488 nm & 514.5 nm
• Nd: YAG – Continous 1065 nm
49. Clinical uses in Eye
• Treatment of lid papillomas
• Treatment of age related keratosis
• Photocoagulation of retina
• Photovaporisation of choroidal tumors
• Posterior capsulotomies
57. APPLICATIONS OF LASER
• INDUSTRIAL
WELDING AND CUTTING
SURVEYING AND RANGING
CUTTING IN GARMENT
INDUSTRY
COMMUNICATION;FIBRE
OPTICS
HEAT TREATMENT
LASER PRINTING
LIGHT EFFECTS
58. MEDICAL USES
INCLUDES TREATMENT OF :
a)Retinal detachment
b)Diabetic retinopathy
c)Neovascularization
d)Posterior capsulotomies
e)Laser trabeculoplasty in open angle glaucoma
f)Laser iridotomy in acute angle closure glaucoma or chronic
angle closure glaucoma
g)Macular degeneration
h)Heavily pigmented tumours of the eye
59. LASER SAFETY
• Lasers are usually labeled with a safety class number, which
identifies how dangerous the laser is:
• Class I/1 is inherently safe, usually because the light is contained
in an enclosure, for example in cd players.
• Class II/2 is safe during normal use; the blink reflex of the eye will
prevent damage. Usually up to 1 mW power, for example laser
pointers.
• Class IIIa/3R lasers are usually up to 5 mW and involve a small risk
of eye damage within the time of the blink reflex. Staring into such
a beam for several seconds is likely to cause (minor) eye damage.
60. • Class IIIb/3B can cause immediate severe eye damage upon
exposure. Usually lasers up to 500 mW, such as those in cd
and dvd burners.
• Class IV/4 lasers can burn skin, and in some cases, even
scattered light can cause eye and/or skin damage. Many
industrial and scientific lasers are in this class.
• The indicated powers are for visible-light, continuous-wave
lasers. For pulsed lasers and invisible wavelengths, other
power limits apply. People working with class 3B and class 4
lasers can protect their eyes with safety goggles which are
designed to absorb light of a particular wavelength.
61. LASER SAFETY
If eyes are not protected adequately when working with laser
beams, severe damage can occur