生物医学信号检测作业

Formulate firing rate at input )2cos()(0θπ++=t f A m t m m

Solution:

Obviously , m m f πω2=，i i t t T -=+1，firing rate T r 1

= With the formula

dt t m m V i i t t th ⎰++=1))((10，we can obtain: )

cos()

cos()2)(cos(2)2sin(

)

2sin()2)(cos(2)]sin()[sin()()2cos()(001010110011

1θωθωθωωωωθωωθωθωωθπ++=⇒++=++⋅⋅

+=+++=+-++

-=++==→+++++++⎰⎰i m th i m t t when i i m m m m i i m m i m i m m i i m t t t t th t A m V T t AT T m t t T T AT T m T

t t A T m t t A

t t m dt t f A m dt t m V i i i i i i

So, the firing rate

th

m V t A m T r )

cos(10θω++==

MATLAB m0=1;

A=1;

w=2*pi/5;

l=pi;

t=0:0.002:12;

v1=1;

v2=2;

v3=3;

y1=(m0+A*cos(w*t+l))/v1;

y2=(m0+A*cos(w*t+l))/v2;

y3=(m0+A*cos(w*t+l))/v3;

figure(1);

plot(t,y1,t,y2,'g',t,y3,'r','linewidth',2) legend('Vth=1','Vth=2','Vth=3',0)

grid;

axis([0 12 0 2.3]);

xlabel('t(s)'),ylabel('Firing Rate(pps)'); title('The Firing Rate Under Different Vth')

Then，we have the following outcome: