- #1

- 5

- 2

## Main Question or Discussion Point

**The problem statement:**

I want to produce an LL-EMF of a specific amplitude and frequency in a pair of Helmholtz coils of pre determined radius.

The frequency and amplitude are derived from the following equations from this publication http://www.heartrhythmjournal.com/article/S1547-5271(14)01477-5/pdf

**Relevant equations:**

I have put the powers of 10 in brackets

Equations derived by Jerry Jacobson, DMD,PhD

1) mc(2) = q(j) v B L

where m =target molecule mass = for vasostatin-1 mol weight of 7KD = 7000 x 1.169 x 10(-24)gm

c =velocity of light =2.99 x 10(10)cm/sec

q(j) = 1 ab-coulomb

v = earth's orbital velocity = 3 x 10(6)cm/sec

L =target linear dimension = 1.73 x 10(2)cm

B =magnetic amplitude in Gauss

2)Based on the aforementioned assumptions and hypotheses, Jacobson then

proposed the desired frequency of the applied electromagnetic field by invoking the

cyclotron resonance equation:

f = qB/2(pi)m

where B =magnetic amplitude in Gauss (derived from above equation)

q =normalized charge of electron = 1.602 x10(-19) ab-coulomb

m =norm. mass of electron = 9.1095 x10(-28)

**My work so far:**

I have worked them through for a human size of 1.73 meters, and get the results as :

B (amplitude in Gauss) = 2.01 x 10(-8)G

f (frequency in Hertz) = 0.56Hz

I can scan and upload my longhand work if needed.

So then to design the Helmholtz coils. Their size should be suitable to centre the magnetic field on the heart area of a human, giving a radius of 35cm (Radius of coils equals distance of separation).

The magnetic flux density at their midpoint is given by:

B =(4/5)(3/2)UnI/R

here U =4PI x 10(-7) T.m/A (permeability of free space)

n = number of turns in each coil

I =current in amps =2.5amps (see below)

R =radius in meters =3.5 x10(-1)

B =derived as above =2.01 x 10(-8)G

I have a frequency generator that outputs 20V p-p maximum, output impedance is 50Ohms, so current should be 2.5 amps

However, when i try to solve the above equation to get the number of turns for the coils, i get 2.37 x10(-3) turns!

Am i using the correct equations?

Thanks,

John

Last edited by a moderator: