Unequal Distribution of Training Diastolic Blood Pressure Labels

TensorFlow
1

My task is to estimate diastolic blood pressure (DBP) from PPG and ECG data. However the DBP labels are distributed unequally.

I am using Diastolic blood pressure as training labels. The range that I am considering is 16mmHg - 276mmHg, however, majority samples lie in the range of 45mmHg - 110mmHg, because of this model is learning this range efficiently, and is not predicting the values outside this range. What can be the solution to this problem?

UnequalDistribution
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3

@Zainab_Jamil,

Welcome to the Tensorflow Forum,

You can try to upsample the minority class and include more samples if possible.

Another way is to use a weighted loss function by providing more weightage to minority class during training.

You can find more information about weighted loss here Imbalanced classification: credit card fraud detection

Thank you!

5

Thanks for your prompt response. I tried the weighted loss function as follows;

def get_weight(label):

if label >= 16 and label <= 45:

return 2.0

elif label >= 110 and label <= 276:

return 1.5

else:

return 1.0 # Assign the default weight to other samples

def weighted_loss(y_true, y_pred):

weights = tf.map_fn(lambda x: get_weight(x), y_true)

loss = tf.losses.mean_absolute_error(y_true, y_pred)

weighted_loss = tf.reduce_mean(loss * weights)

return weighted_loss

but that did not work for me.
Can you please the upsampling the minority DBP range a little for me?

7

@Zainab_Jamil,

Please refer to SMOTE upsampling technique which may help you.

Thank you!