Pulse Amplitude Index; Patented Technology (Ww1020 Only) - BCI WW1020 Operation Manual

Chapter 2: Intended Use and Monitor Features

Pulse Amplitude Index

The PI value is a relative measure of pulse-signal strength over time at a pulse oximeter
monitoring site, and is non-pulsatile in nature. Pulse Amplitude Index is defined as
PI = (100 * AC)/DC where AC is the alternating current (pulsatile component of the signal)
and DC is direct current (non-pulsatile component of the signal). For more information, see
Pulse Amplitude Index in Chapter 4: Operating Instructions.
NOTE! The PI value is a relative value that varies from patient to patient.

Patented Technology (WW1020 only)

This oximeter incorporates patented technology and noise reducing hardware to enhance the
oximeter's ability to detect pulse amplitude in patients with poor peripheral perfusion. Blood
Pulse Detection Method Using Serial Autocorrelation (SAC), patent number 5,558,096, analyzes
a digitized signal, in real time, and compares it with previous pulse data. If similar characteristics
to previous data are recognized, the device confirms a valid pulse. In essence, an individual's
pulse data is retained and used as a template to accept or reject future pulse signals. Patented
technology, digital signal processing, and a greatly improved signal to noise ratio, provide for
improved performance.
Clinician's Operation Manual 2-3