NİLGÜL NALBANT Coordinator of Seminar : Mersini Makropoulou

Laser – Tissue Interactions

CONTENT:

What is the CARDIOLOGY?  CARDIOLOGY is a science which researches anatomy, physiology and pathology of the heart and the vessels.  Disturbances in the heart and vessels are diagnosed and treated by CARDIOLOGY.  All important diseases are defined by CARDIOLOGY

Laser Angioplasty  Laser Angioplasty is one of the methods which is used for defining the injuries.  At the Laser Angioplasty, light energy is transferred to the tissue

The transfer of the light energy into a tissue depends on three factors:  The wavelength of the light  Its power density  The chemical and physical properties of the target

Photon energy in electron-volts of some lasers currently in use or under investigation for medical applications

 The absorption of the laser radiation by the tissue is given by the equation: I* = I e -αL I* = Intensity of the light transmitted I= Intensity of the light beam α= absorptivity of the target tissue L= thickness of the tissue

 If the absorption is strong, the photons penetrate to depth of only 1/10 th to 1/100 th of a mm from the tissue surface.  Strong absorption tends to minimize the thermal damage to the underlying areas because the diffusion of heat from the laser photons is minimized

 The density of the photon stream or power density is one of two factors that control the density of excited molecules in the tissue the instant the light beam strikes.  At the power levels at which lasers operate, the laser- tissue interaction is by no means limited to given molecule’s being excited by just one photon

Time(sn) Photochemical reactions coagulation Vaporization Photo ablation photoabsorption POWER DENSITY

This is explain by:  Fluence = Energy deposited/ area  Power density = Energy deposited / time  Power density = Fluence / time

The overall process of using the photon energy of pulsed laser to cause a transformation in a tissue can be sorted into three individual step: 1. Absorption of the photon 2. Bond breaking 3. Ablation of the products

Irradiation Absorption Bond Breaking Ablation Laser Beam Mask Tissue Long- chain Molecules

What are advantages of The Laser in the Angioplasty? )It differentiates the damaged vessel from the normal vessels. 2)It is used at the tissue catheterization.

ANGIOPLASTY KOCAELİÜNİVERSİTESİTIP F. –CARDIOLOGY LABORATORY

ANGIOPLASTY KOCAELİÜNİVERSİTESİTIP F. –CARDIOLOGY LABORATORY

Anatomic appearanceAngiographical appearance Narrowed artery

 THE ROLE OF ULTRASOUND IN THE INTERVENTIONAL CARDIOLOGY Dr.Cevdet ERDÖL, Doc.Dr.Nazim A R S L A N, Prof.Dr.Dcnlz DEMlRKAN GATA Cardiology ABD, ANKARA