CBSE Class 9 Answered
In medical ultrasound is widely used:
Obstetrics and Gynecology
- measuring the size of the fetus to determine the due date
- determining the position of the fetus to see if it is in the normal head down position or breech
- checking the position of the placenta to see if it is improperly developing over the opening to the uterus (cervix)
- seeing the number of fetuses in the uterus
- checking the sex of the baby (if the genital area can be clearly seen)
- checking the fetus's growth rate by making many measurements over time
- detecting ectopic pregnancy, the life-threatening situation in which the baby is implanted in the mother's Fallopian tubes instead of in the uterus
- determining whether there is an appropriate amount of amniotic fluid cushioning the baby
- monitoring the baby during specialized procedures - ultrasound has been helpful in seeing and avoiding the baby during amniocentesis (sampling of the amniotic fluid with a needle for genetic testing). Years ago, doctors use to perform this procedure blindly; however, with accompanying use of ultrasound, the risks of this procedure have dropped dramatically.
- seeing tumors of the ovary and breast
Cardiology
- seeing the inside of the heart to identify abnormal structures or functions
- measuring blood flow through the heart and major blood vessels
Urology
- measuring blood flow through the kidney
- seeing kidney stones
- detecting prostate cancer early
In addition to these areas, there is a growing use for ultrasound as a rapid imaging tool for diagnosis in emergency rooms.
There have been many concerns about the safety of ultrasound. Because ultrasound is energy, the question becomes "What is this energy doing to my tissues or my baby?" There have been some reports of low birthweight babies being born to mothers who had frequent ultrasound examinations during pregnancy. The two major possibilities with ultrasound are as follows:
- development of heat -- tissues or water absorb the ultrasound energy which increases their temperature locally
- disintegration of cells
- extracting (extract intracellular components or obtain cell-free bacterial enzyme)
- activation (acceleration) of an enzyme reaction in liquid foods
- acceleration of fermentation
- mixing
- homogenizing
- dispersion of a dry powder in a liquid
- emulsifying of oil/fat in a liquid stream
- spraying
- degassing
- inspection, e.g. in the beverage industry
- deactivation of enzymes
- microbial inactivation (preservation)
- crystallisation
- meat processing
- stimulation of living cells
- enhanced oxidation
1. It is used in sonar devices to detect the presence of objects underwater. Hence it is used by submarines, scuba divers and fishing trawlers who use it to detect shoals of fish.
2. It is used in security systems to detect even the slightest movement in a specified area.
3.Ultrasound is used in industry to analyze the uniformity and purity of liquids and solids by means of acoustic microscopy.
4. It is used in humidifiers in which ultrasound waves vibrate a metal sheet to spray the water as a fine mist.
5. Ultrasonic welding is used to create heat to weld plastics.
6. Ultrasonic cleaning is useful to clean delicate articles of jewelry,watches, and lenses.