Reject a nested object if all parameters of its own nested object are blank


I have a model called Sample that has many Treatments. A Treatment
can have many Results.

I want to reject the creation of a Treatment if all its fields are
blank and if all the fields of each of its nested Results are blank.

I have this in the Sample model:

accepts_nested_attributes_for :treatments, :allow_destroy =>
true, :reject_if => proc { |attributes|
attributes['treatmenttype'].blank? && attributes['author'].blank? &&
attributes['results_attributes'].blank? }

This part:

only makes it reject the Treatment if there are no Results, but how
can I write the conditions so that it will reject the creation of a
Treatment if all the attirubtes of each Result are blank? Right now
it creates the Treatment if the Result exists, regardless of whether
all its fields are blank.