Unobtrusive monitoring of the cardio-respiratory
and daily activity for wheelchair users became nowadays an
important challenge, considering population aging
phenomena and the increasing of the elderly with chronic
diseases that affect their motion capabilities. This work
reports the utilization of FMCW (frequency modulated
continuous wave) Doppler radar sensors embedded in a
manual wheelchair to measure the cardiac and respiratory
activities and the physical activity of the wheelchair user.
Another radar sensor is included in the system in order to
quantify the motor activity through the wheelchair traveled
distance, when the user performs the manual operation of
the wheelchair. A conditioning circuit including active filters
and a microcontroller based primary processing module was
designed and implemented to deliver the information
through Bluetooth communication protocol to an Android
OS tablet computer. The main capabilities of the software
developed using Android SDK and Java were the signal
processing of Doppler radar measurement channel signals,
graphical user interface, data storage and Wi-Fi data
synchronization with remote physiological and physical
activity database.