Rejecting noise in a signal
AssigneeDrägerwerk AG & Co. KGaA
InventorChristopher J. Brouse
Life of this patent
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Abstract
Reducing noise in a signal is provided. A first filter includes a selectively definable passband for filtering a first signal used in determining at least one patient parameter. A characteristic analyzer detects a characteristic of a second signal and generates a variability measurement value using a series of data values within the second signal over a previously occurring window of time. A filter controller coupled to the characteristic analyzer uses the variability measurement value to define a characteristic of the passband for the first filter and selectively tunes the passband of the first filter according to the defined characteristic. Related apparatus, systems, techniques, and articles are also described.
Claims17
A patient monitoring device configured to reduce noise in a measured pulse rate signal, comprising:
- a pulse rate sensor operating in a red to infrared electromagnetic spectrum configured to generate a pulse rate signal in response to pulse rate measurements;
- an independently measured heart rate sensor operating outside the red to infrared electromagnetic spectrum configured to generate a heart rate signal in response to heart rate measurements;
- a characteristic analyzer configured to determine a measured heart rate variability based on the heart rate measurements;
- a filter controller configured to dynamically tune an adjustable filter in order to generate a reduced-noise pulse rate signal based on the determined heart rate variability;
- a parameter processor providing a pulse rate output signal based on the reduced-noise pulse rate signal;
- and
- wherein the characteristic analyzer is further configured to determine a predicted heart rate variability, determine a guard band based of the measured heart rate variability and the predicted heart rate variability, determine a frequency passband for the pulse rate signal based on the heartrate variability and the guard band, and dynamically tune the adjustable filter based on the frequency passband.
A method for reducing noise in a measured pulse rate signal, comprising:
- receiving pulse rate measurements in a red to infrared electromagnetic spectrum;
- generating a pulse rate signal based on the pulse rate measurements;
- receiving heart rate measurements, independent of the pulse rate measurements, outside the red to infrared electromagnetic spectrum;
- generating a heart rate signal based on the heart rate measurements;
- determining a measured heart rate variability based on the heart rate signal;
- determining a predicted heart rate variability;
- computing a guard band based the measured heart rate variability and the predicted heart rate variability;
- determining a frequency passband for the pulse rate signal based on the heart rate variability and the guard band;
- dynamically tuning an adjustable filter based on the frequency passband;
- determining a reduced-noise pulse rate signal based on the pulse rate signal and the adjustable filter;
- and
- providing a pulse rate output reflecting the reduced-noise pulse rate signal.
Dependencies are inferred from the claim text.