BME6360
Assignment #1
Spring 2011
Neural Engineering
Prof. Wheeler
This homework introduces students to the use of Matlab.
These may be done with the student version of
Matlab. You do not need to hand these in.
However, it is assumed that you will have gained proficiency
with Matlab for subsequent exercises.
1. The following is a simple computation which is at the heart of neural action potentials, which we will study
in the second part of the course.
Compute the potassium equilibrium potential for a membrane which has a
ratio of potassium concentrations of 10:1 (outside vs. inside).
The formula is 25 mV * log
e
([K
+
]
i
/[K
+
]
o
)
and the Matlab command is:
Veqk = 25*log(1/10)
%
log
is log
e
and
log10
is log
10
Calculate the current through the cell membrane per cm
2
if the membrane potential is 100 mV.
The formula
is (VV
eq, K
) * g
K
.
For squid giant axon, in the resting condition, g
K
= 0.38 mS/cm
2
.
Im = (100  Veqk) * 0.38
% what are the units of
Im
?
2. This computation illustrates simple ways to create vectors and to execute the plot command.
Create a 30
element sequence and an associated time index sequence which contains the square pulse:
pulse(t) = u(t5)  u(t20). The following commands will do this for you:
pulse = zeroes(1:30)
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 PRINCIPE
 Vectors, Dot Product, Signal Processing, Row vector, Word processor, Covariance and contravariance of vectors

Click to edit the document details