Diagnostic device including a method and apparatus for bio-potential noise cancellation utilizing the patient's respiratory signal

In a diagnostic medical imaging device, a method of removing an additive electrical noise component of a noisy bio-potential signal caused by a patient's respiration from the noisy bio-potential signal, the method comprising the steps of:

• sampling the noisy bio-potential signal;
• sampling a noise reference signal associated with the patient's respiration;
• filtering the noise reference signal with only minimal time delay to produce a filtered noise reference signal;
• subtracting the magnitude of filtered noise reference signal from the magnitude of the noisy bio-potential signal;
• outputting a clean bio-potential signal;
• and
• triggering the diagnostic medical imaging device on the clean bio-potential signal to generate an image.

A signal processor for removing electrical noise caused by a patient's respiration from a noisy bio-potential signal, the signal processor comprising:

• an adaptive filter unit having a noise reference input for receiving a noise reference signal associated with the patient's respiration, a clean bio-potential input for receiving a clean bio-potential signal, and a filtered noise reference output for outputting a filtered noise reference signal;
• a summing node having a noisy bio-potential input for receiving the noisy bio-potential signal, a filtered noise reference input for receiving the filtered noise reference signal, and a clean bio-potential output for outputting the clean bio-potential signal;
• a feed-back loop that electrically couples the clean bio-potential output and the clean bio-potential input;
• and
• a feed-forward loop that electrically couples the filtered noise reference output and the input for receiving the filtered noise reference signal.