Operator's Manual

Radical-7 Chapter 1: Technology Overview
www.masimo.com 45 Masimo
Acquisition System
The acquisition system converts the electric signal provided by the sensor
into a digital signal. This format allows the signal to be processed by a
computing device.
Signal Processing
The digital signal produced by the acquisition system is converted into a
measurement that corresponds to the respiratory parameter of interest.
As shown in the previous figure, this can be performed by, for example,
determining the digital signal envelope or outline which in turn may be
utilized to determine the respiratory rate. In this way, a real-time,
continuous breath rate parameter can be obtained and displayed on a
monitor which, in many cases, may be real-time and continuous.
The respiratory cycle envelope signal processing principle is similar to
methods that sample airway gasses and subsequently determine a
respiratory rate.
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[2] Z. Moussavi. Fundamentals of respiratory sounds analysis. Synthesis
lectures on biomedical engineering #8. Morgan & Claypool Publishers,
2006.
[3] Olsen, et al. Mechanisms of lung sound generation. Semin Respir Med
1985; 6: 171-179.