Pulmonetic Systems LTV 950 - Flashing Controls; Dashes; Control Limiting

Page 5-6 LTV
®
Series ventilator Operator’s Manual
p/n 10664, Rev. Y
Flashing Controls
Variable controls and alarms will be displayed solid or flashing. A flashing control means one of the
following things:
• If you are changing a control setting, and the display flashes, you have reached a limited value for
the control. Control Limiting is covered later in this section.
• If an alarm display flashes, it indicates that an alarm has occurred or is occurring. See Chapter 9 -
Ventilator Alarms for more information on this.
• If a control display flashes, it indicates a special condition such as time termination of a pressure
support breath. For more information, see Chapter 6 - Controls.
• If the Control Lock LED flashes, it indicates you have tried to change the control settings while
the front panel controls are locked. For more information, see Chapter 6 - Controls, Control Lock.
Dashes
If a control display is set to dashes “ - - - ”, it indicates that control is turned off, or is not available in
the current ventilation mode.
Control Limiting
Variable control settings may be limited to less than their specified range for any of the following
reasons:
• To prevent inverse I:E ratios of greater than 4:1
• To ensure a minimum inspiration time of 300 ms
• To ensure a minimum exhalation time of 346 ms
• To ensure a minimum initial flow of 10 lpm for Volume Controlled breaths
• To ensure a maximum initial flow of 100 lpm for Volume Controlled breaths
When you are updating a control and have reached a limited condition, the following things happen:
• The control stops updating and will remain displayed at the highest (or lowest) allowed value.
• The control display will flash.
• The displays for other controls involved in the limited condition will flash.
To set the control to a value outside the limited range, you will need to change the settings for other
controls involved in the limit condition. For instance, if the Breath Rate is set to 12, the maximum
allowed Inspiratory Time is 4.0 seconds. To set the Inspiratory Time to more than 4.0 seconds, you
must first decrease the Breath Rate.