Static charge filter for cardiac electrical signals corrupted with static charge and routed to an electrocardiograph (EKG) monitor

An imaging system, comprising:

• a gantry with an examination region;
• an X-ray radiation source configured to produce and transmit X-ray radiation that traverses the examination region;
• an X-ray sensitive detector array configured to detect the X-ray radiation traversing the examination region and generate projection data;
• one or more processors configured to reconstruct at least a sub-portion of the projection data and generate an image indicative thereof;
• and
• a static charge filter for removing static charge in a cardiac electrical signal, comprising:
• a first amplifier configured to amplify an input signal by a first gain, producing an amplified signal, which includes the cardiac electrical signal and static charge from one or more electrodes in a path of an X-ray beam;
• a signal limiter configured to limit a maximum voltage of the amplified signal based on a predetermined clamping threshold, producing a voltage clamped signal;
• a filter configured to filter high frequency components of the voltage clamped signal, producing a filtered signal;
• and
• a second amplifier configured to scale an amplitude of the filtered signal using a second gain so that a cardiac electrical signal in an output signal has approximately a same voltage level as a voltage level of the cardiac electrical signal in the input signal.

A method for removing static charge in a cardiac electrical signal, comprising:

• receiving a cardiac electrical signal from one or more electrodes in a path of an X-ray beam during an imaging examination, wherein the cardiac electrical signal includes static charge;
• removing a static charge voltage spike from the received cardiac electrical signal, producing a static charge filtered cardiac electrical signal by:
• amplifying the received cardiac electrical signal by a first gain, producing an amplified signal;
• clamping a maximum voltage of the amplified signal based on a predetermined clamping threshold, producing a voltage clamped signal;
• filtering high frequency out of band harmonics of the clamped signal, producing a filtered signal;
• and
• scaling an amplitude of the filtered signal using a second gain, which produces an output signal having a voltage level at approximately a voltage level of the input cardiac electrical signal;
• transmitting the static charge filtered cardiac electrical signal to an electrocardiogram monitor, which processes the static charge filtered cardiac electrical signal and produces an electrocardiogram waveform representing an electrical activity of a heart of the subject.