Pulse Oximeter Improvement with an ADC-DAC Feedback Loop and a Radial Reflectance Sensor

Abstract

Pulse oximeter circuitry must meet several design constraints, including the ability to separate a small pulsatile signal component from a large signal baseline. This paper describes pulse oximeter design changes that produced order-of-magnitude improvements in signal quality. The primary changes were (a) the replacement of an analog sample-and-hold-based differentiator circuit with an ADC-DAC feedback loop and (b) the replacement of a side-by-side reflectance sensor design with a radial sensor arrangement that maximizes the pulsatile-to-baseline signal ratio.

Portable Cyber Laboratories For Electrical Engineering Education

“…The investigators on this project have a history of creating effective learning tools for engineering education. [14][15][16][17][18][19][20][21][22][23][24][25][26] One recent product, a RASCL unit, 24 is an analog/digital prototyping tool that forms the initial hardware and software technology base for the learning modules proposed here. It was designed to allow students to complete hands-on laboratory assignments off-campus.…”