-
Notifications
You must be signed in to change notification settings - Fork 0
/
Beam_F3_formula.m
35 lines (31 loc) · 1.26 KB
/
Beam_F3_formula.m
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
function [X,Y] = Beam_F3_formula(TT,NI,CF)
%====================================================================================================================
% This is function is used to calculate X and Y based on Beam F3 method - intended formula version.
% [input]:
% TT: distance from Left tragus to Right tragus
% NI: distance from nasion to Inion
% CF: circumference
% [output]:
% X: the distance X from FPz to point A at the FPz-Oz level along the head circumference.
% Y: the distance Y from the Cz position to a specific point, represented derived F3 position.
% [Reference]
% William Beam et al.,(2009).An efficient and accurate new method for locating the F3 position
% for prefrontal TMS applications.
%
% Zhen Li, 2023, Maastricht university
% ====================================================================================================================
%%
PI = 3.14159265358979323846264338327950;
R2 = TT*0.4;
R1 = NI*0.4;
A = (R2*sind(324)+R1/2)/R2*cosd(324);
B = R1*sind(288)/(R1*cosd(288)-R2/2);
x = 1/2*(R1-R2*B)/(A-B);
y = A*x-R1/2;
r = sqrt(x^2+y^2);
theta = atan(y/x);
Y = r*.9;
X = CF/4 * (90+ theta*(180/PI)) /90;
end