Ablation

Ablation is defined as the removal of material from the surface of an object by vaporization, chipping, or other erosiveprocesses. The term occurs in space physicsassociated with atmospheric reentryand in medicine.

In space physics ablation is used in the context of heat shieldsto protect payloads from heat, such as the heat shields used by the Apollo Command/Service Moduleon atmospheric reentry. There is an entire branch of space physics research involving the search for new materials to achieve the best ablative performance; this function is critical to protect the spacecraft occupants and payload from otherwise excessive heat loading.

In medicine, ablation is the same as removal of a part of biological tissue, usually by surgery. Surface ablation in the skin(also called resurfacing, because it induces regeneration) can be carried out by chemicals (peeling) or by lasers. Its purpose is to remove skin spots, aged skin, wrinkles, thus rejuvenatingit. Surface ablation is also employed in otolaringologyfor several kinds of surgery, such as for snoring. Ablation therapy using radiofrequency waves is used to cure a variety of arrhythmias such as supraventricular tachycardia, WPW syndrome, ventricular tachycardia and more recently atrial fibrillation. The term is often used in the contest of laser ablation, a process by which the molecular bondsof a material are dissolved by a laser.

Surface ablation of the corneafor several types of eye refractive surgeryis now common, using an excimer lasersystem (LASIKand LASEK). Since the cornea does not grow back, laser is used to remodel the cornea refractiveproperties, in order to correct refraction errors, such as astigmatism, myopiaand hyperopia.

External links

• Physics of laser ablation
• Lasik Laser Eye Surgery. USA Food an Drugs Administration info.
• Physical Modalities, Including Laser. eMedicine index of articles on the subject.
• Chemical Peeling. American Academy of Dermatological Surgery.de:Ablation

fr:Ablation (médecine) pl:Ablacja

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It uses material from the http://en.wikipedia.org/wiki/Ablation Wikipedia article Ablation.