Research Challenges in Wireless Networks of Biomedical Sensors 1 Loren Schwiebert Wayne State University Department of Computer Science 1 This material is based upon work supported by the National Science Foundation under Grants ANI and DGE and the Kresge Eye Institute. Sandeep K. S. Gupta Arizona State University Department of Computer Science and Engineering Jennifer Weinmann Wayne State University Department of Electrical and Computer Engineering Additional Authors: Ayad Salhieh, Vikram Shankar, Valliappan Annamalai, Manish Kochhal, and Greg Auner.

“Typical” Future Sensor Node Matchbox Size Battery Powered Power-conserving processor – 100’s of MHz 10’s of MB of program and data memory Radio modem using TDMA Capable of running a scaled down version of Palm OS or Windows CE

Biomedical Smart Sensors?? Smart Sensor – Biomedical sensor/actuator with integrated circuitry Biomedical – Implanted in the human body Form – Small with limited power, encased in inert material Function – Alleviate chronic diseases and disabilities, monitor health

Biomedical Sensors are Unique! Limited Computation and Data Storage Ultra Low Power Consumption Wireless Communication Continuous Operation Inaccessibility Bio-Compatibility – Material Constraints Robustness and Fault Tolerance Secure Data Communications Regulatory Requirements

Example Applications Glucose Level Monitor Transplant Organ Viability Monitor Blood Monitor Retinal and Cortical Prosthesis Cancer Detection/Monitor Health Monitor

Retinal and Cortical Implant

Data Processing and Communication

Smart Sensor Retinal Interface

Functional Block Diagram of the Retinal Neuron Scanner

Research Approach Optimize across protocol layers Organize communication among sensor nodes Develop application-specific solutions Take advantage of biomedical sensor features – fixed topology, pre-defined communication and known membership Generalize these solutions

Research on Fixed Topologies Vary # of Neighbors Trade-offs Exist –Number of Hops –Number of Receivers –Amount of Contention Evaluate Power Usage Test Power-Aware Routing

Research on Fixed Topologies Power-Aware Routing reduces Power Usage 3D is better than 2D 4 Neighbor Topology has lower Power Use Reason is always fewer Receptions Current work includes improving protocols

Research Objectives Strict Power Management Efficient Wireless Spectrum Use Scalability – Support as Many Sensing Elements as Possible Support Diagnostic Functionality Standardize Design with Other Research Groups

Smart Sensors and Integrated Devices Materials Development Device Development and Prototyping Electronic Integration Design Hybrid Technology and Packaging Device Characterization, Testing, and Evaluation Materials Characterization (Microstructure, optical, electrical) Materials Simulation, Device Simulation, Design, and Testing Materials Processing (Special lithography and device fabrication development) Device Simulation Design and Testing Data Communications and Interface Design VLSI Circuit Development Intelligent system Design and Development (Neuronet, logic) Multidisciplinary Research

Smart Sensors and Integrated Microsystems Gregory W. Auner, PhD Pepe Siy, PhD Loren Schwiebert, PhD Vaman Naik, PhD Ratna Naik, PhD Lowell Wenger, PhD Xiaoyan Han, PhD Yuriy Danylyuk, grad student Dan Durisin, engineer Francette Fey, grad student (NSF IGERT) Sam George, research assistant Changhe Huang, PhD Chantelle Hughes, grad student (NSF IGERT) Michael Lukitsch, grad student (NSF IGERT) Marvie Nickola, grad student (NSF IGERT) Mona Safadi, grad student (NSF IGERT) David Sant, grad student Flaminia Serina, M.S. (NSF IGERT) Margarita Thompson, PhD Jennifer Weinmann, grad student (NSF IGERT) Jie Xu, professor Song Xu, PhD Feng Zhong, grad student Ayad Salhieh, grad student (NSF ITR) Manish Kochhal, grad student (NSF ITR) Changli Jiao, grad student Retina and Cortical Implant Project Ophthalmology Gary Abrams, MD Raymond Iezzi, MD Alexander Dizoor, PhD Neurosurgery Pat McAllister, PhD Robert Johnson, MD Janet Miller, B.S. Hun Park, MD, PhD Todd Frances, M.S. Veterinarian Liz Dawe, D.V.M.