ZOLL M Series Defibrillator Rev R - Manual (Page 141)

M Series Service Manual
131
The EtCO
2
option incorporates, without modification, the Novametrix respiratory carbon dioxide technology,
including a printed circuit board, and a patented and proprietary mainstream CO
2
sensor and reusable/disposable
airway adapters. Carbon dioxide measurements are monitored by using a solid-state infrared Capnostat

sensor which
works on the principles of infrared absorption.
The M Series system board software transmits commands to the Novametrix board to set parameters (averaging mode,
oxygen, and nitrous oxide compensation) and retrieves CO
2
waveform, EtCO
2
, and respiration rate data. The M Series
software formats the data for output to the display and strip chart recorder. In addition, the M Series software performs
range checking of the Novametrix data to determine the presence of low or high EtCO
2
and respiration rate alarm limit
violations. If the limits have been violated, the software issues audio and visual alarms.
The Capnostat

mainstream sensor is attached to an airway adapter that connects to an endotracheal tube, similar
airway, or disposable mouthpiece. The sensor generates infrared light and beams it through the airway adapter to a
detector on the opposite side of the airway. As a result of respiration, CO
2
flowing through the airway adapter absorbs
some of this infrared energy. The monitor relates the amount of detected energy to the amount of CO
2
in the airway
adapter. The CO
2
display reflects the maximum concentration of CO
2
detected during expiration. End-Tidal Carbon
Dioxide (EtCO
2
) displays as a numerical value in millimeters of mercury (mmHg), percent (%), or kilopascals (kPa)
on the unit. In addition, a capnogram waveform may display underneath the ECG waveform.
The EtCO
2
option uses Non-Dispersive Infrared (NDIR) absorption and dual wavelength ratiometric-True Single
Beam Optics. The Capnostat

sensor contains the NDIR light source. Carbon dioxide, flowing in the airway adapter
as a result of respiration, absorbs some of this light energy.
Biphasic Waveform
The M Series Biphasic Waveform Defibrillator produces a Rectilinear Biphasic TM waveform similar to the chart shown
at the end of this section. The electrical energy is delivered in two successive current phases of opposite polarity. As
compared to the monophasic waveform, the biphasic waveform typically defibrillates with substantially less current
than the earlier monophasic waveform used by most defibrillators.
The M Series Biphasic Defibrillator system consists of circuitry and software located on the following assemblies:
1. Main System PWBA.
2. High Voltage Module.
3) Biphasic Bridge PWBA Module.