12.7 Clinical Uses of Sound

12.7 Clinical Uses of Sound

• Bats have to be captured and examined in order to get baseline data.
• In one study, the social call of a rare Bechstein's bat was used to lure bats into the net.

• The Mediterranean fruit fly is a pest that can cause $1 billion in damage worldwide.

• The most common way of controlling the medfly is spraying pesticides.
• A more friendly way of controlling the pest has been sought for a long time.
• Sound traps may be an alternative.
• The medfly's wings produce a sound at a fundamental Frequency of 350 hertz accompanied by complex Harmonics.

• Female medflys are attracted to this call and can be lured into a trap.

• Body sounds can be analysed with a stethoscope.
• A hollow flexible tube is attached to a bell-shaped instrument.
• The bell is placed on the skin to amplify the sound of the body.
• The sound is then transmitted to the examiner's ears to evaluate the functioning of the organ.

• Two bells are placed on different parts of the body in a modified version of the stethoscope.
• The sound from one bell is picked up by one ear, and the sound from the other bell is picked up by the other.
• The two sounds are compared.
• It is possible to listen to the heartbeats of the fetus and the pregnant mother at the same time.

• It is possible to produce waves up to millions of cycles per second with special electronically driven crystals.

• Ultrasonic waves are absorbed by tissue.

• It is possible to examine structures within living organisms with X-rays.

• Ultrasonic methods can show motion in some cases, such as in the examination of a fetus and the heart.

• The relative motion between the source and the observer affects the sound's frequencies.

• The minus sign is used when the source is approaching the observer, and the plus sign is used when the source is not moving.

• It is possible to measure motions within a body.

• The sound is altered by the effect of the wind.
• The velocity of blood flow can be obtained by comparing the incident and scattered frequencies.

• The mechanical energy in the wave goes to heat within the tissue.
• Ultrasonic energy can be used to heat parts of a patient's body more efficiently and evenly than can be done with conventional heat lamps.
• It is possible to destroy tissue with high-intensity sound waves.
• lithotripsy is a type of stone that can be destroyed with the use of sputum.

• The intensity of a sound produced by a point source decreases as the square of the distance from the source increases.
• Consider a riveter as a point source of sound and assume that the intensities listed in Table 12.1 are measured at a distance 1 m away from the source.

• Discuss the limitations on the size of the object that a bat can detect with its echo location.

• Estimate the lower limit on the size of objects that can be detected with the sound of a sonic boom.

• Explain the Doppler effect with the help of a basic physics textbook.