Transcript
Transduction of the Electrocardiogram EEE 120 – Electronic Instrumentation
Topics Covered Electrophysiology of the Heart Ionic to Electronic Transduction Instrumentation Design Considerations Electrical Safety Considerations
The Conduction System of the Heart (Origin of the Electrocardiogram)
Transmembrane Potential and Ionic Conductances
Lead II Electrocardiogram Recording
ECG Waveform Nomenclature
ECG Timing and Relationship to Electrical Conduction
The Electrode-Skin Interface
ECG Recording Circuit
Typical Lead II ECG Recording
Electrode Potential Stability
Electrode Materials and Offset Potentials (mV)
Sintered Ag/AgCl Electrodes
EMG and 60 Hz Interference
ECG Bandwidth Requirements
!"#$%&'(")*+#%,-",(./**0102*3*400*561* 57#8(*9#(7*:&%"(&8*+#%,-",(./**012*3*;0*561*
Effects of Inadequate Bandwidth
ECG Amplitude Range (mV x 10)
Burr Brown (Texas Instruments) INA 121 Instrumentation Amplifier
In-Amp with Isolated Ground Circuit
Signal and 60 Hz Noise Level
Sampling Rate and the Phenomenon of Aliasing
Aliasing Analysis
UAF 42 Universal Active Filter
UAF42 2nd Order Low-pass Filter (example)
Bode Plots of Filter Characteristics
Electrical Safety Considerations
Patient Leakage Current Standards
Isolation Transformer
Isolation Amplifiers
Analog Devices AD 210 ISO Amplifier Functional Diagram
Driven Ground Circuit
Driven Ground Circuit
See PSpice Line Fault Current Simulation
PSpice Line Fault Simulation Circuit
I(RE) = Fault Current Passing Through Subject
