The SAV04 Small Animal Ventilator. Contents Page

Transcription

1 The SAV04 Small Animal Ventilator Contents Page SAV04 Ventilator Parts and Controls... 2 General... 4 Basis of operation... 4 Points to note... 5 Using the SAV04 for the first time... 5 The unit controls... 6 POWER OFF/ON (1)... 6 IPPV ON/OFF (2)... 6 Pressure Knob - change & commit (3)... 6 Expiratory Time Knob - change & commit (4)... 6 Solenoid status (10 & 11)... 6 Auto-calibration of the valve assembly... 7 Procedure:... 7 Connecting the hoses and pipes to the valve unit... 8 Patient Connection Kit... 8 Extension Kit... 8 Low Dead Space Kit... 8 Standard use... 9 With Extension Kit... 9 With Low Dead Space Kit Alarm conditions Alerts Appendix A - Conversions Appendix B - Calculating the Fresh Gas Flow (FGF) rate for a T-piece Appendix C - Compliance Appendix D - Specifications Page 1 of 18

2 SAV04 Ventilator Parts and Controls 1. Power ON/OFF 2. IPPV ON/OFF 3. Ventilation Pressure Control 4. Expiratory Time Control 5. Display Window 6. Battery Charging LED 7. Battery Fully Charged LED 8. Battery Fault LED 9. Mains Power LED 10. Solenoid Valve Open LED 11. Solenoid Valve Closed LED 12. Adjustable Feet 13. Rubber protective end boot 14. Ventilator Valve 9W D-Type plug connection 15. USB PC Connection 16. Charger connection 17. Fuse holder (2A) 18. Speaker Grill 19. Ventilator Valve 9W D-Type socket 20. Lock Screws for D-Type socket 21. Valve/Sensor Assembly 22. Exhaust Port (22mm O/D, 15mm I/D) 23. Oxygen Inlet Port 24. Patient Port (22mm O/D, 15mm I/D) Page 2 of 18

3 Main Unit SAV04 Parts and Controls Main Unit Rear Panel Valve Unit Page 3 of 18

4 The SAV04 Small Animal Ventilator General The SAV04 is a pressure-cycled ventilator designed to deliver accurate and repetitive IPPV to animals on a custom T-piece system. The custom T-piece incorporates the valve and pressure sensor and is designed to work with any anaesthetic gas delivery system configured in non-rebreathing mode. The SAV04 ventilator is not designed to be used in a circle or any rebreathing system. There is no requirement for a separate ventilator driving gas as the gas for inflation is derived from the standard Fresh Gas Flow (FGF). All connections are either standard 22mm or 15mm tapered fit. As in manual I.P.P.V. a good quality cuffed Endotracheal Tube and a system free from leaks is essential. It is suggested that the unit is used as a normal T-piece system with the IPPV switch OFF until I.P.P.V. is required. The SAV04 may be fitted with a standard stainless steel valve with 5mm exit orifice or with a black ABS valve with 12mm exit orifice. The recommended use of the SAV04 is for animals up to 12kg. However, in situations where high gas flows can be used economically (such as with oxygen concentrators or with air), the 11mm orifice will allow ventilation of animals up to 40kg in weight. The SAV04 is fitted with a sealed battery to allow use in situations without mains power. In the event of power and/or battery failure the solenoid will fail safe with the valve open. The valve assembly will then act as a standard T-piece and manual IPPV can be given in the normal way. Basis of operation The SAV04 uses a solenoid valve and a precision pressure monitor to perform pressure cycled IPPV on patients using a custom T-piece valve assembly. The sequence of events once the IPPV status is set to ON is as follows: The solenoid valve closes, preventing incoming fresh gas from leaving via the waste port. With no escape route the incoming gas inflates the patients chest at a rate determined by the Fresh Gas Flow rate The pressure monitor attached to the custom T-piece measures the airway pressure and constantly compares it to the Target Pressure set by the Pressure Control knob. When the airway pressure reaches the Target Pressure the solenoid valve opens allowing the patient to exhale passively through the waste port. The solenoid valve remains closed for the period set by the Expiratory Time knob. At the end of the Expiratory time the solenoid valve closes and the whole process repeats. Page 4 of 18

5 Points to note The user cannot set the Inspiratory time. This is determined by the incoming FGF rate and should be set in accordance with normal T-piece function. (see Appendix B) The unit measures the actual inspiratory time and displays it for each breath on the main screen The unit calculates the actual respiratory rate based on the measured inspiratory time and set expiratory time and displays it on the main screen. At any time the actual airway pressure is shown by a bargraph and a value in cm H 2 O on the main screen The system relies on developing a pressure in the patients airway. For this reason a snug-fitting ET tube is required. Any leaks will result in the Target Pressure not being reached. Using the SAV04 for the first time In your ventilator case you will find the following items Large blue Main ventilator control unit Small black valve assembly with attached 9W D-Type cable 9v Power unit Hose connection kits: Standard connection kit Extension kit Low Dead Space kit Remove the ventilator from its packaging and connect the 9W D-Type cable from the valve assembly to the back of the main control unit. Secure it in place by tightening the lock-screws. Do not connect any patient connectors or gas flow at this time. Plug the 9v Power Unit into the mains supply and connect the small plug to the ventilator on the back panel of the main unit. The blue LED at the bottom left of the front pane will be lit. Turn the unit ON. The unit will beep 3 times and display an opening screen with information on the Firmware and Bootloader versions. After 2 seconds this will change to the main ventilator screen. Page 5 of 18

6 The unit controls The controls are very similar to the previous version SAV03 ventilator. POWER OFF/ON (1) This single switch controls the power to the main unit. When the switch is OFF the solenoid in the valve unit will be open and the valve unit can be used as a standard T-piece. Battery charging will still take place when the unit is OFF. IPPV ON/OFF (2) This is a biased flip switch with a normally resting position in the up position. Pressing this switch down once will toggle the ventilator status between IPPV ON and IPPV OFF. The status of the unit will be shown by the text on the screen as either IPPV or OFF. Pressure Knob - change & commit (3) This rotary control changes the value of the Target Pressure shown on the screen. As the control is rotated so the number on the left hand side of the screen changes. If the rotation of the control is stopped, then the final number will flash about once a second on the screen. If the knob is not pushed to commit the new value within 5 seconds then the value will revert to the previous saved value. To save a new value, turn the knob to the desired value and then press and hold the knob until a short beep is heard. Release the knob. The new value is saved and will be used for the next breath cycle. Expiratory Time Knob - change & commit (4) This rotary control changes the value of the Expiratory Time as shown on the lower right hand side of the screen. As the control is rotated so the number on the right hand side of the screen changes. If the rotation of the control is stopped, then the final number will flash about once a second on the screen. If the knob is not pushed to commit the new value within 5 seconds then the value will revert to the previous saved value. To save a new value, turn the knob to the desired value and then press and hold the knob until a short beep is heard. Release the knob. The new value is saved and will be used for the next breath cycle. Solenoid status (10 & 11) The status of the solenoid valve is shown by two LED's. There is a VALVE LED to the right hand side of the screen. When the solenoid valve is OPEN (Expiration) the Green LED will be lit. When the solenoid valve is CLOSED (Inspiration) the Red LED will be lit. Page 6 of 18

7 Before proceeding it is necessary to check that the valve unit is calibrated. At the bottom of the screen between the Pressure value and the Expiratory Time value should be a single value of zero e.g. : If this value is not zero then the unit needs calibration. To do this, follow the section on Auto-Calibration of the valve assembly. Auto-calibration of the valve assembly Every valve unit needs to be calibrated with the main unit it is used with. This is usually only required if the valve unit is new or has been replaced. The procedure is simple and quick to perform and requires no special tools. Make sure that the valve is securely connected at the back of the unit with the lock-screws tightened and that the unit is connected to the mains charger. There must be no pressure in the valve unit during calibration so disconnect all hose connections and/or patients from the valve unit before proceeding. Procedure: Turn the unit ON whilst keeping the Pressure knob (3) pressed in until the opening screen has finished. The screen will then show the following text: AUTO CALIBRATION CONNECT VALVE AND PRESS RIGHT KNOB TO CONTINUE After making sure that the valve is correctly connected, press the EXP TIME knob. The unit will beep once and show the main screen. The pressure value at rest should now be zero. Page 7 of 18

8 Connecting the hoses and pipes to the valve unit Patient Connection Kit C B A Extension Kit D E Low Dead Space Kit G F Page 8 of 18

9 Standard use Connect the oxygen supply hose (A) to the FGF outlet on your anaesthetic machine using the 22mm connector. Connect the other end of the oxygen supply hose to the oxygen inlet port ( 23) of the valve unit. Connect one end of the 15mm waste pipe (B) to the exhaust port (22) of the valve unit. Attach the openended 0.5L bag (C) to the other end of the 15mm waste pipe. Scavenge from the open-ended bag in the usual way. The patient ET tube connector will connect into the patient port (24) With Extension Kit Disconnect the oxygen supply hose from the oxygen inlet port on the valve unit and seal this port with the supplied stopper (E). Connect the smaller end of the extension hose (D) into the 15mm patient port connection (24). Now connect the end of the oxygen supply hose to the 6mm swivel connector at the larger end of the extension hose. The patient ET tube connector will connect into the end of this larger green connector. Page 9 of 18

10 With Low Dead Space Kit Disconnect the oxygen supply hose from the oxygen inlet port on the valve unit and seal this port with the supplied stopper (E). The standard oxygen supply hose (A) is not used in this configuration. Connect the end of the long oxygen hose (F) onto the FGF outlet on your anaesthetic machine. Connect the 15mm ET connector on the end of the short oxygen hose into the patient port (24). The patient ET tube (or luer-fitting catheter) will connect to the small white 2.5mm connector at the centre of the tiny blue Y-piece (G). Sidestream gas sampling can be performed through the self-sealing black rubber disc on the side of the tiny Y-piece using a 24 gauge needle. Note: Waste connection pipe connectors differ between stainless steel and plastic valve housings. With stainless steel housings the 15mm tubing has a 15mm male and one end and a 22mm female at the other. With the plastic housings the 15mm tubing has a 15mm male connector at both ends. Page 10 of 18

11 The Main Display screen The main display screen provides information on settings and measurements performed by the ventilator. Alarm icon Status/Alarm Text Beeper icon IPPV Status Measured Inspiratory Time/TSLB Measured Respiratory Rate Target Pressure Value Airway Pressure Value Pressure Bargraph area Expiratory Time value Alarm icon Shows the status of alarm notifications. To turn Alarm beeps OFF press and hold the Pressure knob until a short high beep is heard. A cross will be placed through the Alarm icon. To turn Alarm beeps ON, press and hold the Pressure knob until a short low beep is heard. The Alarm icon will appear as normal. Beeper icon Shows the status of breath confirmation beeps. To turn breath confirmation beeps OFF press and hold the Expiratory Time knob until a short high beep is heard. A cross will be placed through the Speaker icon. To turn breath confirmation beeps ON, press and hold the Expiratory Time knob until a short low beep is heard. The Beeper icon will appear as normal. IPPV Status Displays IPPV when IPPV is active, otherwise OFF Page 11 of 18

12 Measured Inspiratory Time/Time Since Last Breath The value shown here can represent two possible times. If the patient is being normally ventilated in IPPV mode and the Inspiratory Time is less than 10 seconds then the value show is the last measured Inspiratory Time. This will be updated every breath. If the Inspiratory Time is greater than 10 seconds then the value will count up in seconds, the time showing representing the time since the last triggered breath. When the unit is in OFF mode the value shown will be zero. During IPPV, the I:E ratio will also be displayed just above the IT value. Measured Respiratory Rate The value shown here is the patient's Respiratory Rate calculated from the measured Inspiratory Time and the set Expiratory Time. It is only shown in IPPV mode. In OFF mode the value is replaced with "--" Expiratory Time Value This value is set by the right-hand control knob. Rotating the knob will change the value in increments of 0.1 seconds for values below 2 seconds. For values between 2.0 and 10 seconds the increment is 0.5 seconds and above 10 seconds the increment is 1 second. The maximum value for Expiratory Time is 60 seconds. If the value is changed, the knob must be pressed to commit and save the new value. Target Pressure Value This value is set by the left-hand control knob. Rotating the knob will change the Target Pressure value in increments of 1 across the whole range. The range of values is from 1 to 60 cm H 2 O. If the value is changed, the knob must be pressed to commit and save the new value. Pressure Bargraph Area This small area to the right of the Target Pressure Value is used to draw a vertical bargraph representing the patient's airway pressure. The bargaph region extends from the bottom of the screen to the full height of the Target Pressure digits and this height is always taken as full-scale height. For example if the Target Pressure Value is 20 cm H 2 O then the bargraph will be half the digits height at 10cm and full height at 20cm. If the Target Pressure Value is 14 cm H 2 O then the bargraph will be half-height at 7cm and full height at 14cm. The bargraph area can alert you to possible leaks in the airway system. For example if the Target Pressure Value is 20 cm H 2 O and the bargraph rises to 2/3 height but goes no further, then there must be a leak at around 13 cm H 2 O pressure where the incoming gas flow equals the gas leak. Check for leaks around the ET tube and T-piece circuit. Airway Pressure Value The value shown here is a real-time measurement of the airway pressure in cm H 2 O. The measurement is always made and displayed, even when the unit is in OFF mode. This can be useful if occasional manual breaths are given between Page 12 of 18

13 ventilator breaths because the bargraph height and this Airway Pressure Value indicate the pressure value developed by manually squeezing the bag. Status/Alarm text In this area text is displayed about the status of the unit. When there are no alarms or alerts to report then if the mains charger is not connected, the battery voltage is displayed. If the mains is connected then the text MAINS ON is displayed. In the event of an alarm condition, the alarm message will be displayed here. The possible alarms/alerts are: Alarm conditions NO BREATH! In IPPV mode the Inspiratory Phase has taken longer than 10 seconds. Repeated every 10 seconds unless the Target Pressure is reached. OFFSET ERROR! Auto calibration value is out of bounds. Run the calibration routine. The reported and measured pressure values may be incorrect. OVER_PRESSURE! The unit has detected an airway pressure that is 8cm above the set Target Pressure. VALVE DISCONNECT! The unit has detected that the valve unit is not connected to the main unit. Check the connection at the back of the unit, making sure the lock-screws are tightened. If the problem persists, first try re-calibrating the unit. If that does not resolve the error, call your Vetronic Services support representative. Alerts LOW 5.5V The internal battery voltage is low. When the internal battery voltage falls to 5.5V or less the unit cannot operate normally and the error is raised. Connect to the mains charger. MAINS ON If no alarms or alert conditions are active and the unit is connected to the mains power supply, this status is displayed. BATT 6.1V If no alarms or alert conditions are active and the unit is NOT connected to the mains power supply, this status is displayed. PC CONNECT The unit has detected a PC connected to the USB port. Page 13 of 18

14 Appendix A - Conversions CONVERSIONS. ATMOSPHERIC PRESSURE = 760mm Hg (mercury) = kpa = 1013 millibars = 1033 cm Water. 10 cm Water = 1kPa 1 cm Water = 1 millibar 10 millibars = 1kPa 13.6 cm Water = 10mm Hg As a guide the safe maximum intrathoracic pressure that can be tolerated by a healthy lung (in a closed chest) is of the order of 5-6kPa or 50 to 60cm water before damage occurs. Most cats & dogs are adequately ventilated at cm water. In species with no functional diaphragm (e.g Birds & Reptiles) it is rarely necessary or desirable to use pressures in excess of 15cm H 2 O IMPORTANT NOTE The trigger values and flow rates given are intended to act as a guide only. The actual used values will depend much more on chest compliance and the age and physical state of the individual. Please note that chest compliance is influenced markedly by age, obesity and whether the chest is open or closed. Continual checks and adjustments will need to be made during the various stages of surgery / anaesthesia. Page 14 of 18

15 Appendix B - Calculating the Fresh Gas Flow (FGF) rate for a T-piece The FGF rate for use with a T-piece is calculated based on the required Inspiratory Time and a nominal I:E ratio of 1:2. To calculate the FGF rate for a patient, determine the Tidal Volume of that patient, determine the Inspiratory Time for that patient and then calculate the FGF required to produce the desired volume in the desired time. e.g. patient 4kg, RR=30 If RR = 30, time for 1 breath is 2 seconds. If inspiration is half of expiration, Inspiration must be 0.67s and Expiration 1.33 seconds. (Inspiration=2/3 seconds) TV = 10mls/kg = 40mls. Must deliver that 40mls in 0.67 seconds. 40 mls in 0.67 seconds = 40/0.67 mls/second = 60mls/second = 3.6L/minute OR TV= 40mls, RR=30 so MV = 1.2L/min. Circuit factor is 3 so MV = 3.6L/min. This option is quicker but does not take into account the actual inspiratory time as a fixed I:E value of 1:2 is assumed Page 15 of 18

16 Appendix C - Compliance DECLARATION OF CONFORMITY For: Small Animal Ventilator SAV04 Date: September 1st 2014 It is hereby declared that the following equipment conforms with the essential protection requirements of Council Directive 89/336/EEC relating to Electromagnetic Compatibility. It is further declared that the following equipment conforms to the Low Voltage Directive EN60950 Such equipment is intended for use on animal patients only. Equipment Description: Pressure cycled, Small Animal Ventilator. Model Prefix: SAV Input Voltage: 9V DC Rated power: 18W maximum Intended use: For use in Veterinary practice or animal research establishments for the purpose of providing intermittent positive pressure ventilation (IPPV ) Description: A Class II appliance designed to run from an SELV supply Standards Applied: Safety EMC EN60950 EN Emissions EN Immunity Authorised signatory to this declaration, on behalf of the manufacturer is identified below: Name: Title: Keith Simpson Managing Director Vetronic Services LTD 12 Henleys Business Park Manor Road, Abbotskerswell Newton Abbot Devon, TQ12 5NF Signed.. Keith Simpson, Managing Director, Vetronic Services LTD Page 16 of 18

17 Appendix D - Specifications Mechanical Main unit Dimensions: 180mm x 180mm x 60 mm (excluding feet) Weight: 2kg Construction: Extruded Aluminium with rubber boot fitted at each case end Valve unit Dimensions: 110mm x 90mm x 50mm Weight: 150g Construction: Impact-resistant ABS case Electrical Supply voltage: 9V, 2A DC, Centre Positive 2.5mm connector Power consumption (max) :18 Watts Rear Panel Fuse rating: 2 Amps (T) USB: 2.0 Type B connector. Self-powered USB Slave device (<1.0 ma) General Intended use: Domestic Animals Anaesthetic Apparatus configuration: T-Piece with Oxygen or Air Mode of Operation: IPPV by Outlet Occlusion/Pressure cycled device Target Pressure Range: 0-60 cm H2O Resolution: 1 cm increments Expiratory Time Control: 0.1 to 60 seconds Resolution: 0.1 to 2.0 seconds in 0.1 second increments 2.0 to 10 in 0.5 second increments 10 to 60 in 1 second increments Respiratory Rate Range: 1 to 120 Breaths per minute Page 17 of 18

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