uci bme 140 review
TRANSCRIPT
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BME 140 Review
Michael Klopfer
3/17/2014
Disclaimer: I do not know the exact problems onthe finalthis session will cover major concepts
that I believe are important to your success on
the exam, it is not meant to be a comprehensive
review!
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Offset NullificationA good approach
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Offset NullificationAn alternative (typically not as
good approach)
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Offset NullificationAn alternative (typically not as
good approach)
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Offset NullificationAn alternative (typically not as
good approach)
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Offset NullificationAn alternative (typically not as
good approach)
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Know this circuit, be able to prove it for the exam!
The trick is knowing how to apply kirchhoff's laws for
the coupled non-inverting amplifier at the input
Why are the gains set as they are?
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Why all the leads?
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ECG Leads and Electrical Axis
Ground
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The Heart acts as
a charge pump
This model is used to show the reason why thee leads
show the values they do when differentially amplified
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Interesting Key Point
KNOW THIS!
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Estimating the Cardiac Vector Direction
How can you estimate the cardiac vector by just
knowing the lead voltages? Remember for
(LEAD I, LEAD II, and LEAD III), only 2 leadsare linearly independent, in the set -- the 3rd is
linearly dependent on the other two
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There are several geometric tricks to
calculate/estimate the cardiac vector (either
instantaneous or mean) See class notes or
Watch this video:
https://www.youtube.com/watch?v=jg5X3V5I
PS4
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Left Anterior Descending [LAD] (The
Widowmaker)
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Other Discussed Topics:Destruction of heart anatomy and different contraction patterns
Vulnerable versus stable plaque, coronary artery anatomy
STEMI/NSTEMI/ clinical variants in ECG
12 versus 3 lead ECG (Whats the difference?)
Let go current (What is this, why does it occur)
Effect of electrical frequency on shock
Skin effect
Effect of chronaxie (Very short pulses and depolarization)
How electrosurgery works
Potentiomeer versus filters for DC offset correction
Breakdown of ECG circuitwhat each component does
Electrode typesPolarizable
Non-polarizable
Ion flow / electrolysis
Input impedance of different op-amp circuits
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You should also know:How to prove all op amp circuits from class with Kirchhoff's laws
How to identify various op amp circuits (inverting, follower/voltage buffer, non-
inverting, summing, etc and immediately know the associated gain formulas
and then be able to go and apply the necessary Kirchhoff's laws for the proof
What a potentiometer is and how it can be used for offset correction
The total and complete proof of the instrumentation amplifier using kirchhoff's
laws
Filters and calculating filter impedancePolarizable versus non-polarizable electrodes why to use one versus the other
and what they are
Calculating the cardiac vector (Practice this!)
Effect of frequency on electrical shock and heart disruption
What each part of the ECG circuit does and why it is there
The golden rules of the Op-amp
Heart/muscle physiology and action potentials
The Nernst potential and how it applies to this course
Capacitative coupling and ground loops (electrical safety)
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