Abstract
This letter presents a novel time-based scheme for wireless measurement
of bioimpedance. Conventional circuits measure impedance in the analog
or digital domain, incurring in high power and area consumption
resulting from either the use of analog multipliers and high-order
filters, or high-speed ADCs. Wireless transmission of impedance bits
further results in a power penalty. Time domain solution offer a unique
advantage both in terms of power consumption and technology scalability.
Here we present a system that combines a pulse-width modulation-pulse
position modulation (PWM-PPM) readout with a pulse-harmonic modulation
(PHM) wireless link for power efficient transmission of impedance data.
The paper presents a system-level description of the wireless readout
architecture and its operation simulated in MATLAB/SIMULINK and LTSpice.
The work presented here can provide the foundation for the design of
novel time-based energy-efficient wireless impedance analyzers.