Digital IIR filter with adjustable filter weights based on measured changes in the processed data

A digital filter, comprising:

• a filtering block configured to receive a sequence of input signal values and perform a filtering operation on the received sequence of input signal values, said filtering operation controlled by a plurality of filter coefficients;
• a control block configured to receive the sequence of input signal values, determine a change in input signal magnitude over time with respect to the sequence of input signal values and select values for the plurality of filter coefficients of the filtering block based on the determined change in input signal magnitude over time;
• and
• an amplifying block configured to receive a sequence of source signal values and output the sequence of input signal values to the filtering block, wherein the sequence of input signal values is an amplified version of the sequence of source signal values;
• wherein the amplifying block is configured to:
• subtract a baseline value from the sequence of source signal values, filter a result of the subtraction, amplify a result of the filtering, and add the amplified result to the sequence of source signal values to produce the sequence of input signal values.

A digital filter, comprising:

• a filtering block configured to receive a sequence of input signal values and perform a filtering operation on the received sequence of input signal values, said filtering operation controlled by a plurality of filter coefficients;
• and
• a control block configured to receive the sequence of input signal values, determine a change over time with respect to the sequence of input signal values and select values for the plurality of filter coefficients of the filtering block based on the determined change;
• wherein the filtering block is configured to amplify the sequence of input signal values with a first filtering coefficient, delay a sequence of output signal values from the filtering block, amplify the delayed sequence of output signal values with a second filtering coefficient, and add the first filtering coefficient amplified sequence of input signal values to the second filtering coefficient amplified delayed sequence of output signal values to generate the sequence of output signal values.

A method, comprising:

• filtering a sequence of input signal values to produce a sequence of output signal values, wherein the filtering is controlled by a plurality of filter coefficients;
• determining a change in input signal magnitude over time with respect to the sequence of input signal values;
• and
• selecting values for the plurality of filter coefficients based on the determined change in input signal magnitude over time.

A method, comprising:

• filtering a sequence of input signal values to produce a sequence of output signal values, wherein the filtering is controlled by a plurality of filter coefficients;
• determining a change over time with respect to the sequence of input signal values;
• and
• selecting values for the plurality of filter coefficients based on the determined change over time;
• wherein filtering comprises:
• amplifying the sequence of input signal values with a first filtering coefficient,
• delaying the sequence of output signal values produced by filtering,
• amplifying the delayed sequence of output signal values with a second filtering coefficient, and
• adding the first filtering coefficient amplified sequence of signal values to the second filtering coefficient amplified delayed sequence of output signal values to generate the sequence of output signal values.