Principle of Operation
An infrared emitter and sensor in the device are used to register pulse wave at a finger.
In the existing prototype, the sensor signal is amplified, pre-processed and fed through the USB port to a personal computer. The signal can also be sent wirelessly to a PDA or a remote server.
In the PC, the signal is further processed to extract three groups of pulse wave parameters:
The heart rate and heart rate variability (HRV indicates tension, stability and balance of the autonomic nervous system)
Durations of the four phases of PW (indicate tonus and strength of the heart muscle)
Position of the reflected wave (indicates elasticity of blood vessels)
An overall score is then derived from these parameters and presented to the user. The whole set of parameters can also be presented for some categories of users. Normal (reference) values for each parameter are known.
A correlation between the overall score and status of cardio system has been confirmed in numerous trials.
HRV analysis determines the balance between the two branches of cardio-vascular system