Theory Of Operation - Mallinckrodt INOmax DSIR Plus MRI Operation Manual

Theory of Operation

The INOmax DS Plus MRI provides a constant dose
IR
of INOMAX into the inspiratory limb of the ventilator
circuit. The INOmax DS
IR
channel" design to provide delivery of INOMAX. The
first channel has the delivery CPU, the flow controller
and the MR injector module to ensure the accurate
delivery of NO. The second channel is the monitoring
system, which includes a separate monitor CPU, the
gas sensors (NO, NO , and O
2
interface, including the display and alarms. The dual-
channel approach to delivery and monitoring permits
INOMAX delivery independent of monitoring. This
allows the monitoring system to shutdown INOMAX
delivery, if it detects a fault in the delivery system. For
example, INOMAX delivery will be interrupted should
the monitored NO concentration become greater than
100 ppm for greater than 12 consecutive seconds.
(See Figure 1-20 for a schematic diagram).
1. INOMAX drug is stored as a gas mixture of NO/N
an aluminum cylinder at a concentration of 800 ppm.
2. The cylinder is attached to a high pressure
regulator, which incorporates a pressure gauge
that indicates cylinder pressure when the cylinder
valve is open. The cylinder regulator is attached via
tubing to the INOmax DS
the two NO/N quick connect inlets on the back of
2
the device.
3. The INOmax DS Plus MRI checks the INOMAX
IR
cylinder for the correct expiration date and cylinder
concentration.
4. The INOMAX enters the back of the
INOmax DS Plus MRI, passes through a filter, then
IR
a safety shutoff valve, which is open under normal
operation.
5. A MR injector module is placed in the ventilator
gas flow between the ventilator inspiratory outlet
and the humidifier. Based on the ventilator flow, the
INOMAX cylinder concentration and set INOMAX
dose, the proportional solenoid valve delivers
800 ppm INOMAX into the ventilator circuit via
the MR injector module where it mixes with the
breathing circuit gas flow to achieve the set dose.
This allows the INOmax DS
1-26
Plus MRI uses a "dual-
sensors) and the user
2
Plus MRI using one of
IR
Plus MRI to deliver
IR
a constant dose of INOMAX regardless of the
ventilator flow pattern or breath rate (see Figure
1-21).
6. An internal flow sensor verifies the INOMAX flow
from the proportioning valve, providing feedback
to adjust the flow real time. This assures the
calculated INOMAX flow necessary to achieve
a given dose based on reported MR injector
module flow. A one-way valve separates the
flow sensor from potential reverse flow that may
come from the ventilator circuit.
7. Gas Monitoring - The INOmax DS
gas monitoring system provides monitored
values for inspired NO, NO
sample gas is withdrawn from the breathing
circuit and goes through a water bottle, a zero
valve, a sample pump and finally a sample flow
sensor to the gas monitoring sensors.
in
2
7a. The zero valve allows the gas sensors to
be zeroed (during low calibration) without
having to disconnect the sample line from
the breathing circuit.
7b. The pump and sample flow sensor ensure
a sample gas flow rate is maintained to the
monitoring sensors.
7c. The gas monitoring sensors are
electrochemical; they are specific to each
gas and provide an electronic signal which
is proportional to the concentration of the
gas present.
8. Integrated Pneumatic Backup - The
INOmax DS Plus MRI has an integrated
IR
pneumatic backup system that will supply a
fixed flow of INOMAX at 250 mL per minute into
the injector module. This system is completely
pneumatic and does not rely on electronic
control or power. The system will not allow a
dose to be set on the INOmax DS
the integrated pnuematic backup is in use.
Plus MRI
IR
, and O . The
2 2
Plus MRI if
IR
Part No. 20568 Rev-02
2015-08