Reflectance Oximetry Enabled by Flexible Organic Array of Printed Devices

Prof. Ana Arias received her PhD in Physics from the University of Cambridge, UK in 2001. Prior to that, she received her master and bachelor’s degrees in physics from the Federal University of Paraná in Curitiba, Brazil in 1997 and 1995 respectively. She joined the University of California, Berkeley in January of 2011. Prof. Arias was the Manager of the Printed Electronic Devices Area and a Member of Research Staff at PARC, a Xerox Company.

She went to PARC, in 2003, from Plastic Logic in Cambridge, UK where she led the semiconductor group. Dr. Arias is a co-founder of InkSpace Imaging, a startup company that aims to commercialized flexible MRI coils for pediatric patients. Her research focuses on the use of electronic materials processed from solution in flexible electronic systems. She uses printing techniques to fabricate flexible large area electronic devices and sensors.

The optical method to determine oxygen saturation in blood is limited to only tissues that can be transilluminated. The status quo provides a single-point measurement and lacks 2D oxygenation mapping capability. We have demonstrated a flexible and printed sensor array composed of organic light-emitting diodes and organic photodiodes, which senses reflected light from tissue to determine the oxygen saturation. We use the reflectance oximeter array beyond the conventional sensing locations. The sensor is implemented to measure oxygen saturation on the forehead with 1.1% mean error and to create 2D oxygenation maps of adult forearms under pressure-cuff–induced ischemia.

In addition, we present mathematical models to determine oxygenation in the presence and absence of a pulsatile arterial blood signal. The mechanical flexibility, 2D oxygenation mapping capability, and the ability to place the sensor in various locations make the reflectance oximeter array promising for medical sensing applications such as monitoring of real-time chronic medical conditions as well as post-surgery recovery management of tissues, organs, and wounds.