Ok so in my lecture notes we are given an example calculating the resistance of the heart and i will literally copy down exactly what's in my notes onto here. I missed that lecture, so i'm a bit confused. for starters, the equation doesn't even equal 25
Consider the heart in the centre of the thorax
thorax: phi=30cm (not sure what the symbol phi is)
resistivity = 2ohm m
potential diff = 5mV
R = resistivity x L / a =(2 x 100 x 10^-3)/(pi x 0.625 x 10^-3) = 25ohms
they've used resistivity of the thorax, not the heart then where does 0.625 come from? it's obv in mm
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Help! Electrical Resistance of the Heart watch
- Thread Starter
- 29-03-2011 04:19
- Community Assistant
- 31-03-2011 15:11
phi is clearly diameter, in case you haven't worked that out.
They've done resistivity(thorax) x length(heart)/pi (radius(heart)squared)
Should have given 102.
Of course, if he had taken the diameter measurement when doing those calculations instead of radius, it would have given 25...
As to why the resistivity of the thorax has been used, no idea. Does he use the thorax measurements elsewhere? If so maybe its another misprint.