this presentation contain detail information about vemtilators

1. Ventilators
Operation theatre technology
By :RT RUHKMA RAFAQAT

2. Defination
A medical ventilator (or
simply ventilator in context)
is a machine designed to
mechanically move breathable
air into and out of the lungs,
to provide the mechanism of
breathing for a patient who is
physically unable to breathe,
or breathing insufficiently.

3. Parts of ventilators
While modern ventilators are computerized machines, patients
can be ventilated with
a bag valve mask,
a simple hand-operated bag-valve mask.

4. Ventilators are chiefly used in
intensive care medicine,
home care,
emergency medicine (as standalone units) and
in anesthesia (as a component of an anesthesia
machine).
Uses

5. Working Of Ventilators:
 Get oxygen into the lungs.
 Remove carbon dioxide from the body.
(Carbon dioxide is a waste gas that can be
toxic.)
 Help people breathe easier.
 Breathe for people who have lost all ability
to breathe on their own.

6. How Does a Ventilator
Work?
Ventilators blow air—or air with extra
oxygen—into the airways and then the lungs.
The airways are pipes that carry oxygen-rich air
to your lungs. They also carry carbon dioxide, a
waste gas, out of your lungs.
The airways include your:
 Nose and linked air passages, called nasal
cavities
 Mouth
 Larynx, or voice box
 Trachea, or windpipe
 Tubes called bronchial tubes or bronchi, and
their branches

7. Two general categories:
Controller and the Assister.
Controller:
When a patient is connected to a controller type of
ventilator, his or her respiratory ventilation is
determined by the machine. The device sets the
ventilatory cycle, and any tendency towards
spontaneous ventilation on the patient's part does not
affect the machine and can even oppose it.
Assister:
The assister, on the other hand, is controlled by the
patient and used to augment his or her own ventilation
activities.

8. Ventilator Types
Ventilators for home use are small, lightweight and run on electricity. They can
be powered by the internal battery for brief trips outside the home, and can sit
on a bedside stand, cart or wheelchair and be used for travel.
The two main categories of ventilators include:
 Noninvasive ventilators:
These devices provide breathing support through an external interface, such as
a mask or nasal prongs.
POSITIVE PRESSURE ventilators are noinvasive ventilators...
.
 Invasive ventilators:
Patients on long-term ventilation may require ventilation through an
endotracheal tube inserted through the mouth or nose, or through a
tracheostomy tube inserted into an incision in the in the neck.

9. Further classify ventilators as Negative or
Positive pressure devices.
Negative-pressure
Negative-pressure ventilators are more physiological, in that the body of the
patient is contained in a sealed chamber in which the pressure can be reduced.
This negative pressure is transferred to the space within the thorax, producing
a pressure gradient along the trachea that results in air entering the lungs.
Pressure is then returned to atmosphere, allowing the lungs to recoil to their
original shape and to expel some of their air.

11. Positive-pressure
Positive-pressure ventilators, on the other hand, blow air into the
lungs by increasing the pressure in the trachea. This causes the
lungs to expand due to internal pressure and then to recoil
naturally, expelling a portion of the air once the positive pressure is
removed.

12. Types of positive pressure ventilators
 Volume-cycled ventilators
 Pressure-cycled ventilators
 Flow-cycled ventilators
 Time-cycled ventilators

13. In the volume controlled/volume cycled ventilator, the progression of the
cycles is controlled by the volume of air administered to the patient. Thus, if a
machine is set to cycle on a given volume, it does not cycle until that volume
of air has been administered to the patient. It also has a pressure -override
valve, so that if, while the machine is in the process of administering the set
volume, the pressure exceeds a predetermined maximal value, the ventilator
will cycle whether or not the appropriate volume has been administered.
 Volume-cycled ventilators
 Pressure-cycled ventilators
In the pressure-cycled ventilator, air is administered to the patient until the
pressure reached the predetermined limit, at which time the ventilator
switches to its expiratory portion of the cycle, and the process is repeated.

14.  Flow-cycled ventilators
Flow-cycled ventilators deliver oxygenation until a preset flow rate is
achieved during inhalation.
 Time-cycled ventilators
This means that the negative pressure is applied to the body for a given
period of time and then released for another given period of time before
the process is repeated.
Modern time cycled ventilators are electronically controlled.
Microprocessors are used to establish the cycling or the rate of
ventilation, as well as the ratio between inspiration and expiration
times or volumes. These electronic circuits activate solenoid valves that
regulate the airflow.

15. Continuous positive airway
pressure ventilators increase the
work of breathing by forcing the
user to exhale against resistance.
This ventilator provides a
continuous flow of air at the same
level of pressure during inhalation
and exhalation to help keep the
airway open. This is especially
helpful for obstructive sleep apnea.
But this is not considered a true
ventilator because it doesn’t assist
with breathing.
Continuous positive
airway pressure
ventilators...