Where: Z= the module of the impedance at
θ= phase of the impedance at
The I/Q demodulator takes the v(t) signal and outputs two dc values. These two values are used to extract the impedance
module and phase with a single frequency measurement. Figure 6 shows the block diagram of the implementation. Using the
I/Q demodulator helps reduce power consumption while yielding excellent performance.
3. Verification and measured performance
3.1 Health Hub Demonstration Suite
The figure below shows up the Health Hub measurement setup hardware description. The app requires a PC, a BlueRadios USB
Serial Dongle along with the Foot BCM data acquisition system. The pictured device connects to the app via Bluetooth low
energy.
Figure 7 Health Hub Measurement Setup Hardware Description
3.2 Health Hub App
3.2.1 Interface Overview
Health Hub is designed to allow the control and display of many BLE enabled health monitoring devices on a single screen. The
screen is divided into multiple discrete areas, Figure 8, called Device Controls and each area allows a specific BLE enabled health
monitoring device control.
3.3 Demonstration usage
Terminology:
Advertising mode
: the Bluetooth radio is broadcasting advertising data; this allows another device to initiate a connection to
the advertising device.
Device
: a piece of hardware required for a demo.
BlueRadios USB
Serial Dongle
Foot BCM
