Design and analysis of artifact-resistive finger photoplethysmographic sensors for vital sign monitoring

A miniaturized, telemetric, photoplethysmograph sensor for long-term, continuous monitoring is presented in this thesis. The sensor, called a "ring sensor," is attached to a finger base for monitoring beat-to-beat pulsation, and the data is sent to a host computer via a RF transmitter. Two major design issues are addressed: one is to minimize motion artifact and the other is to minimize the consumption of battery power. An efficient double ring design is developed to lower the influence of external force, acceleration, and ambient light, and to hold the sensor gently and securely on the skin, so that the circulation at the finger may not be obstructed. To better understand the mechanism of motion artifact by external forces, a comprehensive mathematical model describing the finger photoplethysmography was developed and verified by finite element method, numerical simulation and experiments. Total power consumption is analyzed in relation to the characteristics of the individual components, sampling rate, and CPU clock speed. Optimal operating conditions are obtained for minimizing the power budget. A prototype ring sensor is designed and built based on the power budget analysis and the artifact-resistive attachment method.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2000

Author dc:creator

• Rhee, Sokwoo

Advisor dc:contributor.advisor

• Harry H. Asada and Boo-Ho Yang.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/32706

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/32706