US 12,329,545 B2
Filtering apparatus, method, program, and recording medium
Tomonori Yanagida, Miyagi (JP); Yoshiyuki Hata, Miyagi (JP); and Yuji Ogata, Miyagi (JP)
Assigned to ADVANTEST CORPORATION, Tokyo (JP)
Appl. No. 17/758,409
Filed by ADVANTEST CORPORATION, Tokyo (JP)
PCT Filed Feb. 5, 2021, PCT No. PCT/JP2021/004372
§ 371(c)(1), (2) Date Jul. 6, 2022,
PCT Pub. No. WO2021/181969, PCT Pub. Date Sep. 16, 2021.
Claims priority of application No. 2020-042153 (JP), filed on Mar. 11, 2020.
Prior Publication US 2023/0018890 A1, Jan. 19, 2023
Int. Cl. A61B 5/00 (2006.01); A61B 5/243 (2021.01)
CPC A61B 5/725 (2013.01) [A61B 5/243 (2021.01); A61B 5/7203 (2013.01); A61B 2562/0223 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A filtering apparatus comprising an FIR filter that has multipliers arranged to multiply input digital data having their respective different input time points by respective variable tap coefficients, wherein
the variable tap coefficients are each switched from a first tap coefficient to a second tap coefficient sequentially for the input digital data from later to earlier input time points,
the first tap coefficient is arranged to cause the FIR filter to serve as a low-pass filter with the cut-off frequency set at a first frequency,
the second tap coefficient is arranged to cause the FIR filter to serve as a low-pass filter with the cut-off frequency set at a second frequency different from the first frequency, and
the variable tap coefficients are switched for each multiplication by one of the multipliers.