Pulse oximetry 2

Question 1

Define Beer’s law

Answer 1

states that when light is transmitted through a clear substance with a dissolved solute, the intensity of transmitted light decreases as the concentration of solute increases

Question 2

Define Lamberts law

Answer 2

States that when a light falls on a homogenous substance, the intensity of transmitted light decreases as the distance through the substance increases

Question 3

At what wavelength is oxyhaemoglobin absorbed?

Answer 3

red light
660nm

Question 4

Name the parts involved in the measurement of oxyhaemoglobin

Answer 4

-LED
-Phototransistor- detects intensity of transmitted light

Question 5

What does it mean if there is less red blood in contrast to redder blood?

Answer 5

less- lower O2 saturation, less absorption, more transmission

redder- higher oxygen saturation, more absorption, less transmission

Question 6

Describe the relationship between light transmitted and finger size

Answer 6

smaller finger- less absorption= greater transmission
larger finger-more absorption = less transmission

Question 7

Whats the wavelength of infrared?

Answer 7

940nm

Question 8

What do pulse oximeters measure?

Answer 8

-the oxygen saturation of haemoglobin in arterial blood
-the pulse rate in beats per minute, averaged over 5 to 20 seconds