Economical Anesthesia Machine Cwm-201A

• Type: Anaesthesia Machine
• Kind: Operating
• Certification: CE, ISO13485
• Group: Adult and Children
• LCD Display: With LCD Display
• Economical Anesthesia Machine: Economical Anesthesia Machine
• Model NO.: CWM-201A
• Transport Package: Standard Export Packing
• Specification: ISO, CE
• Trademark: CW
• Origin: China
• HS Code: 90189070
• Production Capacity: 5000PCS/Year

Product Description

Physical specifications
Demension:70x85x140cm,weight:65kg,screen:10.1 LCD
display graphics:wave forms P-T,F-T,V-T

working specifications
power:AC110V-240V,50HZ/60HZ, battery power:≥180 mins

Pipeline supply gas:O2,N2O

ventilator specifications
patient range:adult,peadiatric
ventilation mode:VCV,SIMV,MANUAL,STAND-BY

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:-20-0 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:4 tubes cascade 0-15L/min O2,0-15L/min N2O,
volume of CO2 absorber:2L , vaporizer: 1/2 piece 

Monitoring:VT,MV,BPM,Paw,LUNG compliance

Equipment main structure and working principle

Complete machine

Structure

The equipment mainly comprises:

1. Anesthesia ventilator;
2. Flowmeters;
3. Anesthetic vaporizer (Enflurane or Isoflurane or Sevoflurane),);
4. Anesthesia ventilation system
5. Machine stand;
6. Oxygen fault alarm and protection device; etc.

Refer to Fig.1 for outline of complete machine.
















1 Flow meter      2 Anesthetic breathing machine 
3 Anesthetic vaporizer     4 Nitrous oxide pressure gauge
5 Oxygen pressure gauge 6 Machine stand
7 Oxygen flush button     8 Castor
9 Breathing circuit system        10 Airway pressure gauge

                           Fig. 1 Outline of complete machine

Working principle

1. 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. Counterclockwise rotation of the flow control valve is increasing the flow, while clockwise rotation is decreasing the flow. After gas sources (O₂ and N₂O) enter the equipment, they are adjusted by flow meter flow control valve to required flow or proportion. Via the anesthetic vaporizer, these are transmitted to the respiration system through common gas (fresh gas) outlet, and this part of gas is referred to as common gas (fresh gas). Concentration of anesthesia gas is controlled by vaporizer. When concentration adjustment knob is turned to "0", output common gas shall contain no anesthesia gas.
2. Among O₂ entering the equipment, one line will directly reach oxygen flush switch. Oxygen output by oxygen flush will pass common gas outlet and enter anesthesia ventilation system.
3. One each of two lines of O₂ entering the equipment is fed to oxygen fault alarm device and N₂O cutoff protection device respectively. When O₂ pressure is lower than 0.2MPa, the equipment will send an audible alarm, while cutting off N₂O supply.
4. Another line of O₂ is fed to ventilator as driving gas.

1. Common gas transmitted to anesthesia ventilation system is stored in ventilator Bellows (if "Machine control" is selected). At this time, respiration of patient is controlled by ventilator. Or, this gas is stored in manual control breathing gas storage bag (if "Manual control" is selected), at which time respiration of patient is controlled by manual pinching of breathing gas storage bag.
2. During inhalation, gas output by ventilator Bellows (or manual control breathing gas storage bag) and common gas pass CO₂ absorbent, inhalation valve, inhalation gas connector, threaded pipe, "Y" connector, and then into patient lungs.

1. During exhalation, gas exhaled by patient passes "Y" connector, threaded pipe, exhaled gas connector, and exhalation valve, and returns to ventilator Bellows (or manual control breathing gas storage bag), to complete a cycle. Excessive gas will be vented via ventilator relief valve (or APL valve).

 

Anesthesia ventilator

Functions

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 bag 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 bag 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.

 
 

Oxygen flush switch

The oxygen flush switch is used to supply high-flow oxygen to the anaesthesia ventilation system through fresh air output port

1. Press oxygen flush switch, supply high-flow oxygen

1. Loosen oxygen flush switch, airflow paused

 

Anesthetic 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 Sevoflurane vaporizer with temperature, flow and pressure 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 valves;
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
5 Manual control breathing gas storage bag connector 6 CO₂ absorbent
7 Oxygen concentration monitoring port    8 Exhalation valve
9 Inhalation valve   10 "MC-AC" selection knob

Fig. 4 Anesthesia ventilation system

 

Main control parts

1. Inhalation valve and exhalation valve

Inhalation valve(1) and exhalation valve(2) are one-way valves
controlling direction of respiration gas flows.
Inhalation valve and exhalation valve separated consist of:
valve hood(1),(2) and valve disk(3),(4).
With respiratory movement of patient, inhalation valve disk and exhalation valve disk open and close alternatively. When the patient
-inhales, inhalation valve disk opens and exhalation valve disk closes, so that gas output by breathing circuit system passes breathing pipeline and enters patient respiratory tract;
-exhales, inhalation valve disk closes and exhalation valve disk opens, so that gas exhaled by patient passes breathing pipeline and enters breathing circuit system.
 

1. CO₂ absorbent (cycle absorbent assembly)

-Functions
CO₂ absorber contains CO₂ absorbent. The absorbent can absorb the patient's exhaled gas, and transfer the generated O₂ to the patient.
-Structure
CO₂ absober 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 (gas bag) or mechanical ventilation (ventilator).
When
-"MC-AC" selection knob is turned to     "Manual" , the patient's breathing
 is controlled manually;
-"MC-AC" selection knob is turned to    "Machine", 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.
-Turning 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;
-Turning 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.

 

System drive 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;