07-03-2011, 11:48 AM
Presented By:
Modi Tejas
Panchal Jay
Pandya Narendra
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Spo2 measurement using ECG
Abstract
ECG is the most basic electric potential of our body. In fact any the disease related to the heart can be easily determined using this “ECG”. But in our body each and every activity is interrelated with each other. From a minute cell to any system such as cardiac system, respiratory system is interrelated. Each and every signal coming out from the brain is related with the various muscular activities, various metabolic activities are related with the pumping activity of our heart and also on various muscle movements.
Till now we have technology where we can measure parameter of one system by using one technique i.e. using ECG we can only determine the parameters of cardiac system but not able to determine the parameters of respiratory. In our project we tried to solve this limitation by using ECG we can measure SPO2 in the arterial blood. To establish the relationship between heart rate and SPO2 we have taken help of applied mathematics.
Introduction
HEART RATE- No of times our heart beats per minute. The normal heart rate of a normal adult person/human is around 70-72 beats/min and the respiration rate is 12-15 breaths/min.
CARDIAC OUTPUT: The cardiac output is the amount of blood ejected from the heart. If the hear rate is 70-72 per minute then cardiac output would be 5litres per minute. This increases during the exercises.
STROKE VOLUME: The amount of blood expelled by each contraction of the ventricles is the stroke volume. When increased blood supply is needed to meet increased tissue requirements of the oxygen and nutrients, heart rate or stroke volume can be increased.
SPO2: oxygen saturation, which is the ratio of summation of concentration of oxyhaemoglobin and concentration of hemoglobin to the concentration of oxyhaemoglobin.
Now the intake of oxygen (VO2) during one minute is 5 lit/min.
As we know,
VO2 = Stroke Volume* Heart Rate
& CARDIAC OUTPUT (C.O) = Stroke Volume*Heart Rate
So we can say VO2 is directly related to C.O.
VO2 =Cardiac Output
Now taking 72 breaths as a standard value at that time the value of Cardiac Output (C.O.) is 5lit/min so for X pulses (diseased condition) we can determine the value of Cardiac Output (C.O.)
Cardiac Output = (number of pulses)* 5/72
Considering normal beats i.e. 72 beats/min the saturation of oxygen in the arterial blood (SPO2) is 100% so for x heart beats (diseased condition) we can determine the saturation of oxygen in the arterial blood (SPO2).
SPO2 = (number of pulses)* 100/72
Requirement of project
1. 15 & 5 volt power supply, CRO, frequency generator.
2. Instrumentation Amplifier.
3. Notch filter.
4. Low pass filter.
5. Comparator.
6. Microcontroller IC.
7. LCD display.
