Cardiac artifacts can be removed from respiration waveforms by receiving a stream of respiration samples of a sensed respiration signal that collectively characterize respiration data for a patient. In addition, heart rate data is received that specifies a heart rate for the patient that is measured concurrently with the sensed respiration signal. Each respiration sample in the stream is continuously and adaptively filtered to result in a corresponding filtered respiration signal that removes cardiac artifacts. This filtering subtracts an earlier respiration sample having a delay equal to a period corresponding to the heart rate of the patient from the then current respiration sample. The filtered respiration signals can then be promoted. Related apparatus, systems, techniques, and articles are also described.
