Principles Of Operation; Pneumatic System Operation; Breath Delivery Characteristics; Control Variable - Philips Respironics V60 User Manual

Chapter 4

Principles of operation

Pneumatic system
operation
High-
pressure
oxygen
Ambient
air
Breath delivery
characteristics
4-2
The ventilator uses ambient air and high-pressure oxygen (Figure 4-1). Air
enters through an inlet filter. Oxygen enters though a high-pressure inlet, and a
proportioning valve provides the operator-set concentration. The system mixes
the air and oxygen, pressurizes it in the blower, and then regulates it to the
user-set pressure. To do this, the ventilator compares the proximal (patient)
pressure measurement with the ventilator outlet (machine) pressure, and
adjusts the machine pressure to compensate for the pressure drop across the
inspiratory filter, patient circuit, and humidifier. This helps ensure accurate
and responsive pressure delivery and leak compensation.
Respironics V60 Ventilator
O pressure
2
Propor-
O flow
2
tioning
sensor
valve
Air flow
sensor
Air inlet
filter
Figure 4-1: Respironics V60 Ventilator gas delivery system
The ventilator delivers gas to the patient through a main flow (inspiratory)
bacteria filter, a single-limb patient breathing circuit, a humidification device
(optional) and a patient interface such as a mask or ET tube. A pressure tap
proximal to the patient is used to monitor patient pressure. The exhalation port
continually exhausts gas from the circuit during inspiration and exhalation to
minimize rebreathing and ensure CO

Control variable

Breaths delivered by the Respironics V60 Ventilator are pressure controlled. In
the AVAPS mode, the ventilator's applied pressure is automatically adjusted
over a period of time to maintain a target tidal volume.

Triggering, cycling, and leak adaptation

Unlike other ventilators, the Respironics V60 Ventilator does not require you to
set triggering and cycling sensitivity or to adjust baseline flow.The ventilator's
unique Auto-Trak Sensitivity algorithm adjusts these automatically; see "Auto-
Trak Sensitivity" on page 4-3.

Baseline pressure

A positive baseline pressure (EPAP or CPAP) may be set for all breaths in all modes.
Respironics V60 Ventilator User Manual
Proximal (patient)
pressure
Ventilator outlet
(machine)
pressure
Mixer Blower
removal.
2
Patient
Exhalation
port
Main flow
filter
1047358 Rev N