Lasers are a source of very intense light in the ultraviolet, visible or infrared regions of the spectrum. To produce laser light, large numbers of atoms must first have their electrons raised to very high energy levels. As the electrons fall back to lower energy levels, light is emitted. Solids, liquids and gases have all been used as 'lasing'materials. The articles describe a range of medical uses of lasers.
1 Find out what LASER stands for.
2 Which two types of laser are specifically mentioned in the articles?
3 a) Give two reasons why a laser that can be used to cut bone may be a significant medical advance. b) Why was the bone cutting laser tested on animals and cadavers first? c) State two purposes for which lasers have been used in operating theatres in the past. d) American studies had suggested that there may be problems with using lasers to cut bones. What were the problems? e) Fibre-optic cables work on the basis of total internal reflection. What is meant by this term? f) Give two other uses of i) lasers and ii) fibre-optics.
4 a) What kind of laser light can be used to help prevent tooth decay? b) What happens to the enamel of the tooth when the laser is used? c) Why doesn't this damage the teeth? d) When the laser was used with fluoride treatment, dental cavities could be prevented. Suggest two ways of providing regular fluoride treatment.
5 a) What is the retina and what does it do? b) Some people suffer from diseases of the retina that can lead to blindness. Which two diseases are mentioned in the article? c) Using the information in the article, draw a diagram to show how such a device would work. d) What is the biggest problem to be overcome before the device can be used in humans?
