Multi-bit adc with sigma-delta modulation
CA 2556754 C · Owner: Nellcor Puritan Bennett Llc · Inventors: Shea, William; Petersen, Ethan; Chew, Bradford B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An oximeter uses a sigma-delta modulator and a multi-bit ADC (54) with PWM feedback (56) enabling high precision multi-bit conversion. Demodulation is done in software, thus requiring only a single hardware path for both red and IR. Multiple capacitors are switched into the integrator (44) in the sigmadelta modulator, with different capacitors for red IR and dark signals, thus , enabling the use of the single hardware path. A switching circuit (76) at the input of the sigma-delta modulator acts as a sample and hold controlled by , the PWM feedback (56).
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed February 24, 2005 and granted June 11, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 24, 2025.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.