P13071 – Non-Invasive Blood Glucose Monitor Team Members Jared Bold Yongjie Cao John Louma Andrew Rosen Dan Sinkiewicz Faculty Advisor Professor George Slack (EE) Customer Dr. Jayanti Venkataraman (EE)

Overview Develop a non-invasive real time monitoring system that measures blood glucose Improve the accuracy of current non-invasive measurement system Obtain a transmission signal and perform a vector measurement

Team Roles John -Microcontroller configuration -RF Simulation -Procurement Yongjie -Schematic and PCB layout -PCB Population Jared -Microcontroller programming -Communication -Documentation Dan -RF Path -MATLAB development -Schematic Andrew -Project Leader -Antenna design and testing -RF Path -Calibration system

Project Needs and Specs Customer NeedCustomer Specification Accurate measurement of resonant frequencyAccurate to 15 KHz of network analyzer Calibration SystemCalibration time of < 60 seconds Reflection AntennaNarrow band, with resonant frequency ≈ 1.1 GHz Transmission AntennaWide band, with minimum bandwidth from 800 MHz to 2 GHz High resolution dataMeasurement intervals of < 60 seconds Verify antenna performance in real-timeDisplay resonant frequency and sweep data is it is aquired

System Architecture

Concepts – Measurement System Critical to operation of device -Generated the RF signal at the desired frequency -Ensured the signal reaches antenna with maximum power and minimum error -Measures the reflected and transmitted signal

Concepts – Data Acquisition Microcontroller serves as middleman for device -Reads the voltage outputs from the AD8302 -Digitizes values and sends to PC via USB

Concepts – Data Analysis and Display MATLAB Measure Command flow chart Reads continuous stream of data from device and stores/displays the data in real-time.

Concepts – Data Analysis and Display MATLAB Calibration Command flow chart Reads continuous stream of data from device and stores off the calibration data to be used later to compensate for phase error in measurements

Components – Reflection Antenna Design and Simulation

Components – Reflection Antenna Measured Return Loss

Components – Transmission Antenna Design and Simulation

Components – Transmission Antenna Measured Return Loss

Components and Layout RF Synthesizer – ADF4351 Vector Measurement – AD8302 Microcontroller – MSP430F5427A

Testing

Component/System Testing Individual testing of each system Verification of power supply and regulation Communication between MCU and USB Communication between board and host PC Communication between MCU and RF Synthesizer Continuity of RF path and verification of components Correct output of when using test signals on the AD8302 Verification of correct frequency output of RF Synthesizer with spectrum analyzer

Device Testing Test free space resonant frequency Test against sugar water Three different levels of sugar concentrations Solution is comprised of Water = 66.9%, Salt = 0.8%, Sugar = 25%, Flour = 7.3% Test against human body Use fast acting glucose tablets to raise blood-glucose Compare with real blood glucose monitor Find a diabetic to make one final test

Results

Success or Failure? Overall, the device was designed to meet/exceed the specifications given All aspects of the device function individually, however the design ultimately does not function. The board was not matched to 50Ω at our designed frequency of 1.1 GHz, making it impossible to determine the resonant frequency of the antenna. We didn’t anticipate the shift in impedance and we could have resolved the issue with some sort of tuner

Matlab GUI

Suggestions for Future Work – Advice to next group Have a dedicated QA person for each system of the device Ensure that at least one member of the team has RF circuit board design experience Design the board for a smaller bandwidth Get the development boards for everything, regardless of cost Develop a working product with dev boards and antenna. Then make PCB. Buy doubles/extras of all components Develop standards for testing procedure

Opportunities for Improvement Properly matched RF path Make path simpler to remove parasitic effects from chips Implementation of a more robust calibration system Calibrate out magnitude and phase Enhanced communications between MATLAB and device On board processing 360⁰ Phase measurement using two AD8302s