High End Anesthesia System Cwm-302

Physical specifications
Demension:70x85x140cm,weight:65kg,screen:12.1 LCD
display graphics:wave forms P-T,F-T,V-T ,
loops:P-V,V-F,F-P(zoom in/out ,freeze,comparison)
working specifications
power:AC110V-240V,50HZ/60HZ, battery power:≥180 mins
Calibration:auto
Pipeline supply gas:O2,N2O,air
ventilator specifications
patient range:adult,peadiatric
ventilation mode:VCV,A/C,SIMV-V,AIMV-P,MANUAL,STAND-BY,PCV,PSV
ventilator parameter
working type:electronic control ,pneumatic driven
tidal volume:20-1500ml ,pressure range:5-60 cmH2O
RRR:1-100bpm,, I:E range:4:1-1:8
Ptrigger range:-20-20 cmH2O,,
minute volume range:>18L/min
System 
Hypoxic guard system:N2O cut off valve,
O2 concentration>25%, safety valve:<12.5kPa
O2 flush:25-75L/min
flow meter:5 tubes cascade 0-15L/min O2,0-15L/min N2O,
0-15L/min AIR

volume of CO2 absorber:2L , vaporizer: 2/2 piece 
Monitoring:VT,MV,BPM,Paw,LUNG compliance,inspiratory platform, FiO2
PEEP
type:intergrated electronic control ,
range:off/ 3-30cmH2O
Prospective usage
Used for inhalation anesthesia, breathing control or assistant breathing, monitoring and displaying the ventilation parameters of the patient.

Function

1. CWM-302 anesthesia system is Continuous gas flow inhalation anesthesia system; it can be used for closed, semi-closed, semi-open inhalation anesthesia during the operation. Ventilation function can provide the mechanical ventilation for the recovered patient during or after the operation, also monitor and display the respiratory parameters.
2. Suitable for adult or child (≥5kg)

Adaption disease

1. Suitable for inhaled anesthesia, intravenous general anesthesia patient.
2. Suitable for assistant or control respiratory patient.

Contraindication





As to the anesthesia sysem there is no absolute contraindication. But the operator should read the instruction of the anesthesia medicine first, should strictly follow the use range. Please refer to the anticipated use mentioned in the instruction. Care should be taken for heart, liver, and kidney disease patient.
But the operator should pay attention to the relevant contraindication of mechanical ventilation. For example the patient with grave lung disease should not use or use ventilator with great caution.







The main structure and working principles
Main unit
Structure

1. Anesthesia ventilator
2. Flow meter
3. Vaporizer(Enflurane, isoflurane and sevoflurane)
4. Anesthesia ventilation system
5. Frame
6. O₂ faulty alarm and protection

See Fig 1 the structure of anesthesia system





























Fig 1 the structure of anesthesia system
Working principles

1. Gas source (O2, N2O,AIR) enter into the system, it is regulated by the flow control valve of the flow meter to the desired flow or proportion and then, through the anaesthesia vaporizer, is sent to the breathing system through the fresh gas (mixed gas) outlet; this gas is called fresh gas (mixed gas). Anaesthesia gas concentration is controlled by the vaporizer. When the evaporation concentration regulating knob is turn to "0" position, there is no anaesthesia gas in the outputted fresh gas.
2. Another loop of O2 that has entered the machine reaches the oxygen flush button directly. The oxygen outputted from the oxygen flush enters the breathing loop system through fresh gas outlet.
3. There are still two loops of O2 that has entered the machine, which go to oxygen fault alarm device and N2O cut-off protection device respectively. When O2 pressure is lower than 0.2 MPa, the machine gives audible alarm, and cuts off N2O supply at the same time.
4. The fresh gas sending to the breathing loop system is stored in the leather bag of the ventilator (when ventilator is used, and "AC" is selected). Then, the patient's breathing is controlled by the ventilator; or manually control the breathing leather gas storage bag (when ventilator is not used, and "MC" is selected). Then, the patient's breathing is controlled manually by pinching the breathing gas storage bag.
5. When inhaling, gas outputted from the ventilator's leather bag (or manually controlled breathing gas storage bag) and fresh gas are sent to the lungs of the patient through CO2 absorber, breathing flap, inhaling gas connector, threaded tube and "Y" connector.
6. When exhaling, the gas exhaled by the patient returns to the ventilator's leather bag (or manually controlled breathing gas storage bag) through "Y" connector, threaded tube, exhaling gas connector, and breathing flap, completing a circulation process. The excessive gas is discharged out by the safety valve of the ventilator (or APL valve).

Anesthesia ventilator
Function
The anesthesia ventilator provides patient with aux. or controlled ventilation during operation and resuscitation after operation, and monitors, controls and displays patient ventilation parameters.
 

Structure

The ventilator mainly consists of:

1. Front panel operation keys;
2. Sampling sensor;
3. Respiration monitor;
4. Computer control system;
5. Adjustment and control mechanism;
6. Driving mechanism;
7. Display;
8. Fault alarm and safety protection device etc.

  Refer to Fig.2 for ventilator front panel.1 Display screen  2 Operation key zone       3 Tidal volume adjustment knob
Fig.2 Ventilator front panel

Working principle

Refer to Fig.3 for ventilator working principle block diagram, in which hollow arrows are used for gas circuits, and single line arrows are used for electric circuits.










Fig.3 Ventilator working principle block diagram

1. After gas source (O₂) enters anesthesia system, it will reach respiration control valve inlet.
2. During inhalation, respiration control valve opens and expiratory valve closes. Oxygen pushes peltry in breathing Bellows via flow regulating valve, so that patient obtains required tidal volume. The flow regulating valve adjusts gas flow (tidal volume) supplied to patient.
3. During exhalation, respiration control valve closes and expiratory valve opens. Gas exhaled by patient pushes peltry in breathing Bellows in reverse direction, so that gas (oxygen) in Bellows passes expiratory valve and gas exhaust, and is then vent to atmosphere.
4. According to ventilation parameters set by panel operations, Micro PC control board processes airway pressure and tidal volume acquired by pressure sensor and flow sensor, and then controls respiratory frequency, inspiratory time, expiratory time, and tidal volume etc. At the same time, monitored respiration parameters will be displayed on front panel.
5. According to alarm parameters set by panel operations, in case monitored respiration parameters exceed alarm parameter settings, micro PC control board will prompt and send audible alarm.
6. When airway pressure reaches set pressure of safety valve (not exceeding 6kPa), the safety valve will automatically open to prevent excessive gas passage pressure resulting in compressive injury to patient air passage.

Flow meter

Functions

The flow meter is equipped with flow control valve, which controls and indicates the flow of common gas (fresh gas) supplied to patient. O₂, N₂O proportion control device can ensure concentration of the output O₂ is≥25 %.
 

Structure

1. The flow meter is a type of O₂, N₂O four-tube rotor flowmeter. O₂ and N₂O flow meters are composed of thick tubes and thin tubes respectively. The fine tubes are of low flow range; and the thick tubes are of high flow range.
2. The flow meter is equipped with flow control valve. Flow and proportion of O₂, N₂O in the output fresh gas is controlled respectively by corresponding flow control valve. Anticlockwise rotation of the flow control valve is increasing the flow, while clockwise rotation is decreasing the flow.
3. The flow control valve of O₂ and N₂O is equipped with O₂, N₂O proportion control device, so as to ensure concentration of the output O₂ is≥25 %. When O₂ is closed, N₂O is closed automatically at the same time.

 

O₂ flush button

O₂ flush button provide high-flow oxygen to the anesthesia system by the ACGO gas inlet:

1. Press the button to input high-flow oxygen;
2. Release the button to stop the gas flow.

 

Vaporizer

!  Warning:
When the vaporizer completed by the anesthetic machine manufacturer is not going to be used, the vaporizer matched with the anesthetic machine and designated by the manufacturer must be used. Otherwise, their performance would be decreased. 

1. Anesthetic vaporizer is used for accurate control of the anesthetic gas concentration transferred to fresh gas.
2. This equipment can be equipped with one or two CW II enflurane, isoflurane, Halothan and Sevoflurance vaporizer with temperature, flow and presuure compensation function. The user should state it when placing order.
3. The vaporizer has self-locking, mutual locking device.
4. Desired anesthetic concentration can be obtained simply by turning the concentration-adjusting knob.
5. For details of the vaporizer, please read the technical operation manual for vaporizer.

 

Anesthesia ventilation system (breathing circuit) 

Functions

1. Transferring fresh gas (common gas) containing or not containing anesthetic gas to patient;  
2. Absorbing the CO₂ that is exhaled by the patient and transferring the generated O₂ to the patient;
3. Providing a passage to control the patient's inhaling and exhaling; 
4. Exhausting the excessive gas and waste gas.

Structure

Anesthesia ventilation system mainly comprises:

1. Breathing Bellows;

1. Inhalation and exhalation flappers;
2. CO₂ absorbent (cycle absorbent assembly);
3. "MC-AC" selection valve;
4. "APL" valve (adjustable pressure limiting valve, exhaust valve);
5. Excessive gas discharge port etc.

For outline of anesthesia ventilation system, see Fig. 4.

1.  Breathing Bellows  
2.  "APL" valve (adjustable pressure limit valve) knob
3. Inhaling gas connector 4.  Exhaling gas connector

1. Manual control breathing gas storage bag connector
2. CO₂ absorbent
3. Oxygen concentration monitoring port        8.  Exhalation flapper

1.  Inhalation flapper   10.  "MC-AC" selection knob

Fig. 4 Anesthesia ventilation system

Main control parts

1. Inhalation flapper and exhalation flapper

Inhalation flapper and exhalation flapper are one-way valves controlling direction of respiration gas flows. These flappers consist of flapper hood and flapper disk.
With respiratory movement of patient, inhalation flapper disk and exhalation flapper disk open and close alternatively. When the patient
-inhales, inhalation flapper disk opens and exhalation flapper disk closes, so that gas output by breathing circuit system passes breathing pipeline and enters patient respiratory tract;
-exhales, inhalation flapper disk closes and exhalation flapper disk opens, so that gas exhaled by patient passes breathing pipeline and enters breathing circuit system.

1. CO₂ absorbent (cycle absorbent assembly)

-Functions
CO₂ absorbent contains CO₂ absorbent. The absorbent can absorb the patient's exhaled gas, and transfer the generated O₂ to the patient.
-Structure
CO₂ absorbent is installed at bottom of the anesthesia ventilation system, composed of absorbent housing, screen, and internal sleeve. The capacity of this equipment CO₂ absorbent is approx. 2000mL. Capacity of CO₂ absorbent of this equipment is about 2000mL.
For CO₂ absorbent structure, see Fig. 5.














1.Screen      2. Absorbent      3. Internal sleeve    4. Gas flow direction
Fig.5 CO₂ absober structure

1. "MC-AC" selection knob

To select manual ventilation (bag) or mechanical ventilation (ventilator). When
-"MC-AC" selection knob is turned to "   ", the patient's breathing is controlled manually;
-"MC-AC" selection knob is turned to "    ", the patient's breathing is controlled by the ventilator.
 

1. "APL" valve  (adjustable pressure limit valve, exhaust valve)

"APL" valve is used for adjusting the pressure limit value of the anesthesia ventilation system during manually controlled ventilation. When the pressure in the system exceeds the limit value, the pressure is relieved by the excessive gas exhaust port.
-Turn clockwise of the "APL" valve knob increases the pressure limit value of the respiratory system. When turning clockwise to the end, the valve closes, and the pressure limit value is approx. 7.0kPa then;
-Turn counterclockwise of the "APL" valve knob decreases the pressure limit value of the respiratory system. When turning counterclockwise to the end, the "APL" valve opens completely, and the pressure limit value is approx. 0.04kPa then, gas in the respiratory system is exhausted directly through excessive gas exhaust port.
 

Pneumatic gas circuit

Gas supply

1. Gas enters the system through gas supply input connector. The gas supply input connector includes 1 O₂, 1 N₂O and 1 spare O₂ input connector.
2. All the gas supply input connectors are provided with marked connector, filter and check valve;
3. After gas enters the system, it is also connected with pressure relieve valve (approx. 780kPa) to prevent the system from bearing too high pressure;
4. Gas supply pressure gauge displays the gas pressure entering the system;
5. If bottled gas is used as the gas supply, bottle pressure regulator must be used to reduce the bottle pressure to meet the system requirement.