HME 2222: BIOPHYSICS
FOR
BTECH. IN MEDICAL ENGINEERING
DR. NJENGAH
SCHOOL OF PURE AND APPLIED SCIENCES
KIRINYAGA UNIVERSITY
, CHAPTER ONE
INTRODUCTION
Biophysics is the field that applies the theories and methods of physics to understand how
biological systems work.
1. SOUND
Ultrasound
Ultrasound is sound that has a wave frequency higher than the human ear can detect.
It includes all sound with wave frequencies higher than 20,000 waves per second, or 20,000
hertz (Hz).
Although we can’t hear ultrasound, it is very useful to humans and some other animals.
Uses of Ultrasound
1. Echolocation
This is the use of echoes from ultrasound to identify the location of objects that organisms
cannot see.
Uses of echolocation
i. Animals use echolocation to find prey
ii. Used to avoid running into objects in the dark.
iii. Bats uses echolocation to find insect prey.
iv. Visually impaired individuals use echolocation to evaluate their surroundings to enable
them to detect obstacles in the path of travel.
Factors that affect echolocation
i. Quality of the signal
ii. Surface characteristics
iii. Ambient noise
iv. Quality of hearing
FOR
BTECH. IN MEDICAL ENGINEERING
DR. NJENGAH
SCHOOL OF PURE AND APPLIED SCIENCES
KIRINYAGA UNIVERSITY
, CHAPTER ONE
INTRODUCTION
Biophysics is the field that applies the theories and methods of physics to understand how
biological systems work.
1. SOUND
Ultrasound
Ultrasound is sound that has a wave frequency higher than the human ear can detect.
It includes all sound with wave frequencies higher than 20,000 waves per second, or 20,000
hertz (Hz).
Although we can’t hear ultrasound, it is very useful to humans and some other animals.
Uses of Ultrasound
1. Echolocation
This is the use of echoes from ultrasound to identify the location of objects that organisms
cannot see.
Uses of echolocation
i. Animals use echolocation to find prey
ii. Used to avoid running into objects in the dark.
iii. Bats uses echolocation to find insect prey.
iv. Visually impaired individuals use echolocation to evaluate their surroundings to enable
them to detect obstacles in the path of travel.
Factors that affect echolocation
i. Quality of the signal
ii. Surface characteristics
iii. Ambient noise
iv. Quality of hearing
