Ventilator machine

A presentation slide made for the course Clinical Engineering for Bio-medical Engineering students. For educational purpose only.

1. Ventilator machine Hasibul Hasan Hredoy

2. Definition A ventilator is a machine designed to provide Mechanical ventilation by moving breathable air into and out of the lungs, to deliver breaths to a patient who is physically unable to breathe or breathing insufficiently

3. Fig: portable ventilator

4. Possible users COPD Undergoing surgery Acute lung injury Apnea with respiratory arrest Stoke/ brain injury

5. History 1928 Iron Lung 1930 – 1950 Negative pressure devices 1950 Ventilator using positive pressure source

6. Type Of Ventilators Transport ventilators Intensive-care ventilators Neonatal ventilators Positive airway pressure ventilators

7. components

8. Principal of operation 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 includes: 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

9. The Breathing Tube A ventilator blows air into your airways through a breathing tube. One end of the tube is inserted into the windpipe and the other end is attached to the ventilator. The process of inserting the tube into the windpipe is called intubation. Usually, the breathing tube is put into the windpipe through your nose or mouth. The tube is then moved down into the throat. A tube placed like this is called an endotracheal tube. In an emergency, you're given medicine to make you sleepy and ease the pain of the breathing tube being put into the windpipe. An endotracheal tube is held in place by tape or with an endotracheal tube holder. This holder often is a strap that fits around the head. Sometimes the breathing tube is placed through a surgically made hole called a tracheostomy . The hole goes through the front of the neck and into windpipe. The tube put into the hole sometimes is called a "trach" tube. The procedure to make a tracheostomy usually is done in an operating room. Specially made ties or bands that go around the neck hold the trach tube in place. For the most part, endotracheal tubes are used for people who are on ventilators for shorter periods. The advantage of this tube is that it can be placed in an airway without surgery. Trach tubes are used for people who need ventilators for longer period .

10. The Ventilator Positive pressure breaths from the ventilator are typically delivered through an endotracheal tube or a tracheostomy tube. During each positive-pressure breath, the lungs expand in proportion to the volume of gas delivered until a preset pressure, volume, or time limit is reached. A valve then opens to relieve pressure in the lungs, allowing the patient to passively exhale. A critical care ventilator typically consists of a flexible breathing circuit, a control system, a gas supply, and monitors and alarms.

11. How it is done

12. Block diagram

13. Modes Each mode is different in determining how much work of breathing the patient has to do. Volume mode: • 1. CMV or CV • 2. AMV or AV • 3. IMV • 4. SIMV

14. Pressure mode 1- Pressure-controlled ventilation (PCV) 2- Pressure-support ventilation (PSV) 3- Continuous positive airway pressure (CPAP) 4- Positive end expiratory pressure (PEEP) 5- Noninvasive bilevel positive airway pressure ventilation (BiPAP)

15. Control Mode Delivers pre-set volumes at a pre-set rate and a pre-set flow rate. The patient Can’t generate spontaneous breaths, volumes, or flow rates in this mode.

16. Assist Control Mode •Delivers pre-set volumes at a pre-set rate and a pre-set flow rate. •The patient CANNOT generate spontaneous volumes, or flow rates in this mode. •Each patient generated respiratory effort over and above the set rate are delivered at the set volume and flow rate .

17. SYCHRONIZED INTERMITTENT MANDATORY VENTILATION (SIMV) Delivers a pre-set number of breaths at a set volume and flow rate. Allows the patient to generate spontaneous breaths, volumes, and flow rates between the set breaths. Detects a patient’s spontaneous breath attempt and doesn’t initiate a ventilatory breath – prevents breath stacking

18. SIMV Machine breaths: - Delivers the set volume or pressure Patient’s spontaneous breath: -Set pressure support delivered Mode of ventilation provides moderate amount of support Works well as weaning mode

19. Pressure Regulated Volume control • This is a volume targeted, pressure limited mode. (available in SIMV or AC) • Each breath is delivered at a set volume with a variable flow rate and an absolute pressure limit. • The vent delivers this pre-set volume at the LOWEST required peak pressure and adjust with each breath.

20. Pressure regulated volume control A control mode, which delivers a set tidal volume with each breath at the lowest possible peak pressure. Delivers the breath with a decelerating flow pattern, which is less harmful to lung.

21. POSITIVE END EXPIRATORY PRESSURE (PEEP ): • This is NOT a specific mode but is rather an adjunct to any of the vent modes. • PEEP is the amount of pressure remaining in the lung at the END of the expiratory phase. • Utilized to keep otherwise collapsing lung units open while hopefully also improving oxygenation. • Usually, 5-10 cmH2O

22. Continuous Positive Airway Pressure (CPAP): • This is a mode and simply means that a preset pressure is present in the circuit and lungs throughout both the inspiratory and expiratory phases of the breath. • CPAP serves to keep alveoli from collapsing, resulting in better oxygenation.

23. Combination mode Combination modes combine features of pressure and volume targeting to accomplish ventilatory objectives which might not be fulfilled by either used independently. Combination modes are pressure targeted, partial support is generally provided by pressure support and full support is provided by Pressure Control.

24. Problems & Solution Problems Solutions Risk of acquiring ventilator associated pneumonia (VAP). Following proper infection control procedures in maintaining the ventilator, breathing circuit, artificial airway, and all associated equipment can minimize patient risk. Leak in breathing circuit and it’s component. Ventilator should signal an alarm if leakage occurs. Patient fighting the ventilator. Proper maintenance and avoiding operator error or machine failure can reduce the risk.

25. PPM

26. Purchase consideration should offer assist/control and SIMV modes. It should also provide CPAP/PEEP and pressure support. The unit should monitor airway pressure, respiratory rate, I:E ratio, and minute volume; controls should be available for ventilator mode, pressure level, tidal volume, respiratory rate, flow rate FiO2, PEEP/CPAP, I:E ratio, pressure support, and trigger sensitivity Alarms, both visual and auditory, should be available for airway pressure, low CPAP/PEEP, minute volume , respiratory rate , gas supply loss, and power failure. Should include O2 Analyzer. Clearly Identifiable controls and their functions.

27. Continue Maintenance Costs Environmental Consideration Good human factor design

28. Manufacturer Acoma Medical Industry Co Ltd Air Liquide Medical Systems France Bio-Med Devices Inc CareFusion Respiratory Covidien Nellcor Draeger Medical Inc

29. This Photo by Unknown Author is licensed under CC BY-SA-NC

30. References: https://doi.org/10.1016/j.compbiomed.2018.04.016 (journal)