function avedir = DM(ECG_1)
% find peak values
peaks = r_peaks(ECG_1);

% get the peak value and the 10 indices before it (total of 11 points)
peakreg_ind = [peaks(1)-10:1:peaks(1);
                peaks(2)-10:1:peaks(2);
                peaks(3)-10:1:peaks(3)];

time_diff = 0.008;
ioi = 0.08;

grads = [gradient(ECG_1(peakreg_ind(1,:))',time_diff);
         gradient(ECG_1(peakreg_ind(2,:))',time_diff);
         gradient(ECG_1(peakreg_ind(3,:))',time_diff)];

for x=1:1:3
   if ~isempty(find(grads(x,:) < 0, 1))
       grads(x,:) = grads(x,:) - min(grads(x,:));
   end
end

avedir = mean(grads);