Asee peer logo

A Small, High Fidelity Reflectance Pulse Oximeter

Download Paper |

Conference

2007 Annual Conference & Exposition

Location

Honolulu, Hawaii

Publication Date

June 24, 2007

Start Date

June 24, 2007

End Date

June 27, 2007

ISSN

2153-5965

Conference Session

Laboratories and Computer Simulation in BME

Tagged Division

Biomedical

Page Count

14

Page Numbers

12.115.1 - 12.115.14

Permanent URL

https://peer.asee.org/2793

Download Count

347

Request a correction

Paper Authors

biography

David Thompson Kansas State University

visit author page

David Thompson is a Fulbright Fellow currently studying in Japan. He received his B.S. in Electrical Engineering from Kansas State University University in May, 2006. His areas of research interest include biomedical sensors, neural prosthetics, embedded systems design, and analog & digital circuitry.

visit author page

biography

Steve Warren Kansas State University

visit author page

Steve Warren is an Associate Professor of Electrical & Computer Engineering at Kansas State University. He teaches courses in linear systems, computer graphics, biomedical instrumentation, and scientific computing. Dr. Warren manages the KSU Medical Component Design Laboratory, and his research focuses on plug-and-play, wearable systems for telemedicine.

visit author page

Download Paper |

Abstract
NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

A Small, High-Fidelity Reflectance Pulse Oximeter David Thompson, B.S. and Steve Warren, Ph.D. Department of Electrical & Computer Engineering Kansas State University, Manhattan, KS, 66506, USA

Abstract Pulse oximeters have become standard equipment in both biomedical education and clinical settings. Since the operational principles of a pulse oximeter are straightforward, and since the analysis of these sensor data require basic computational and mathematical toolsets, this type of device is well suited to hands-on experiences geared toward both undergraduate and graduate students. However, this seemingly simple type of biomedical device offers challenges in the areas of motion artifact reduction, light excitation/collection, signal fidelity, and parameter extraction that provide rich material for undergraduate and graduate education and research. This paper addresses a new design for a silver-dollar-sized reflectance pulse oximeter that is easy for students to use and incorporates multiple design enhancements that result in high-quality photo-plethysmograms. The pulse oximeter communicates with a LabVIEW virtual instrument via a serial USB interface. The double sided pulse oximeter board contains surface mount circuitry on one side and a reflectance sensor on the other side, where large area photodiodes are arranged radially around a central, dual red & near-infrared LED excitation source. The pulse oximeter is unique in that it is entirely digitally controlled and adjusts signal baselines depending on existing light levels. Additionally, it provides high fidelity red and near-infrared plethysmograms that demonstrate hundreds of analog-to-digital converter levels from peak to valley. Because the plethysmograms are unfiltered, they are good candidates for education and research projects that address signal filtering, blood oxygen saturation calculation algorithms, physiological parameter extraction from photo-plethysmographic signals, light/tissue interaction modeling, and the use of photo-plethysmograms in applications such as biometric authentication. These new devices have been employed in (a) a Fall 2006 lecture/laboratory pair within a biomedical instrumentation course sequence taken by undergraduate and graduate students, (b) undergraduate honors research experiences, and (c) graduate signal processing research.

I. Introduction Blood oxygen saturation, often referred to as the sixth vital sign, can be obtained via a well known, empirically discovered technique referred to as pulse oximetry.1, 2 In recent decades, pulse oximeters have become a staple in clinical environments and are therefore an expected element of any biomedical engineering curriculum. At a conceptual level, the operational principles of pulse oximetry are straightforward and easily conveyed in the classroom; pulse oximeters are therefore attractive for undergraduate hands-on laboratories. However, pulse oximeters intended for practical monitoring environments offer design challenges in the areas of motion artifact reduction, light excitation/collection geometries, wearability, power management, and physiological parameter extraction. This makes them ideal targets for educational design projects and independent research efforts at both the undergraduate and graduate levels.3, 4

Thompson, D., & Warren, S. (2007, June), A Small, High Fidelity Reflectance Pulse Oximeter Paper presented at 2007 Annual Conference & Exposition, Honolulu, Hawaii. https://peer.asee.org/2793

ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2007 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015