The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 25, 1997
Filed:
May. 19, 1994
James R Brooks, Beaverton, OR (US);
SpaceLabs Medical, Inc., Redmond, WA (US);
Abstract
A digital high-pass filter derived from a digital low-pass filter of conventional design. The digital low-pass filter periodically calculates respective low-pass filter output values. Corresponding high-pass filter output values are then calculated by subtracting the low-pass filter output values from input samples provided by digitizing an input signal. The high-pass filter output values are then used to generate samples which are applied to a digital-to-analog converter for outputting a high-pass filtered replica of the input signal. The digital high-pass filter compensates for sudden, relatively large changes in the input signal by comparing the low-pass filter output value to the input sample and, in the event that there is a large discrepancy therebetween, setting the low-pass filter output value to the input sample before calculating the high-pass filter output value.