BME 101
ELECTROBIOLOGY

This course introduces fundamental concepts in the behavior of excitable tissues, such as nerves, muscle fibers, and cardiac tissue. The topics include:

1. Introduction to BME 101. Tutorials: Electrophysiology of excitable tissues. Introduction to cardiac electrophysiology and electrocardiography. Review of vector calculus.

2. Membrane biophysics. Structure of an excitable membrane and its RC circuit analog. Stimulation and strength-duration relationship. Ionic basis of rest potential. Nernst-Planck equation, Nernst potential, Donnan equilibrium, Goldman equation. Parallel conductance model.

3. Hodgkin-Huxley model. Hodgkin and Huxley experiment. Voltage clamp. Mathematical description of potassium and sodium currents. Numerical implementation of the Hodgkin-Huxley model. Physiological phenomena studied with the Hodgkin-Huxley model: excitation thresholds, refractoriness, accommodation, anodal break.

4. Passive fiber. Core-conductor model, governing equations and electrical analog. Steady-state solution for the transmembrane potential during stimulation with point electrodes. Time evolution of the transmembrane potential during stimulation. Time-dependent solution using Laplace transform.

5. Active fiber and propagating action potential. Core-conductor model of an active fiber. Ionic basis of propagation, local current circuits. Uniform propagation. Velocity of propagation versus fiber radius. Numerical simulation of the propagating action potential.

6. Electrical sources and fields. Potential, field, and current density generated by monopole and dipole sources. Extracellular potential generating by an active fiber. Fiber source models, monopole and dipole layer approximations. Distributed and lumped sources. Potential generated by moving monopole and dipole sources.

7. Cardiac electrophysiology. Cardiac action potential and models of cardiac membrane. Automaticity. Conduction system and sequence of activation in the heart. Dipole layer representation of activation wavefront. Heart vector. Electrocardiogram, standard electrocardiographic leads. Connection between the heart vector and EKG. Lead vectors.

Prerequisites: BME 153 / EE 62 (or equivalent) and MTH 111 (or equivalent) or consent of the instructor.

Computer: Some labs and homeworks require programming in Matlab.

Grading: tests: 45% (15% each); labs: 45%, homeworks; 10%.