DIVEDED IN TO TWO PARTS• ELECTRICAL SYSTEM• PNEUMATIC SYSTEM
ELECTRICAL SYSTEM• Master switch• Battery back up• Battery recharge• Electric outlet for in built monitor• Circuit breaker
PNEUMATIC SYSTEM• High pressure system• Intermediate pressure system• Low pressure system
HIGH PRESSURE• From cylinders to the pressure regulating valve/ preset valve.• Convert variable pressure flow from cylinders to lower and most constant pressure suitable for machine• 760 Psi, 1800 Psi to 40-48 Psi
INTERMEDIATE PRESSURE• Receives gases from pressure regulating valve or pipeline & supply to the flowmeters & oxygen flush valve.• 40 – 55 Psi from pipeline• 40 – 48 Psi from pressure regulating valve
LOW PRESSURE• From flow regulating valve to common gas outlet.• Pressure in this system is slightly above the atmospheric pressure• 14 -20 Psi
7PIN INDEX SYSTEM • machine – pins • Cylinder – holes • Pins – 4 mm in dia • 6mm in length, 12° • 9/16 inch radius 7 • O2 – 2,5 • N2O - 3,5 • Air – 1,5 • Entonox -7 • Cyclopropane -3,6
LIMITATIONS OF PIN INDEX• Broken pin• Upside down yoke block• Use of double washer
HANGER YOKE ASSEMBLY• WASHER • FILTER• GASKET• Must be present • Acc to ASTM• Placed around standards. the nipple• Only one washer • 100 µm should• Two nullify pin be installed in index system between cylinder• Must be in good & reducing valve condition
CHECK VALVE ASSEMBLY• One way valve• Prevent gas leak from empty yoke• Allow cylinder change while using one• Prevent transfilling of cylinder• Yoke block, not to keep empty• cylinder closed – pipeline used.
INTERMIDATE PRESSURE• LEAK – • GAS POWER connection OUTLET inside machine • Supply to ventilator or jet• ASTM ventilating system • PRESSURE < 50 Psi not allowed -• Leak should not ventilators will not be more than 25 function ml/min at normal service pressure • Quick coupler • DISS
MASTER SWITCH • INTERMIDATE SYSTEM • Downstream the inlet • Oxygen flush will work even if standby position • Sudden turn off is dangerous
OXYGEN PRESSURE FAILURE DEVICES• OXYGN FAILURE • OXYGEN SAFTY – ASTM FAILURE ALARM• Set pressure o2 • ASTM conc. should not < • < Set P (30Psi) 19% • Initiated within 5 sec . • May be silenced not more than 120 sec. • Can’t disabled
LIMITATIONS oxygen failure safety device• System may be pressured for weeks if it is gas tight; without being connected to the oxygen source.• Do not offer total protection against hypoxic mixture
QUICK FLUSH SYSTEM • 35 – 75 lit/min • 40 - 55 Psi • Percutaneous catheter – adequate ventilation • Work even when master switch off. • Collar to prevent accidental activation.
LIMITATIONS OF OXYGEN FLUSH• ASTM it should • Flush valve not increase or sticking in ON decrease P at position leads to vaporizer outlet > 10 KPa • BAROTRAUMA or output > 20 % • AWARENESS• CHECK VALVE IN MACHINE
SECOND STAGE REDUCING DEVICE• Just upstream the N2O & O2 control valve.• Gases from pressure reducing valve or central supply.• N2O – 26 Psi• O2 – 14 Psi• Flow will be constant below normal fluctutation range
FLOW REGULATING VALVE • Touch, placement, PARTS color coding. • Difference with gases. • Chemical name • Link - mechanical, Pneumatic system • Pin seat system • Stop collar
PROBLEMS WITH FLOW CONTROL VALVE• Inadvertent • Leak through the alteration - open flow control Light valve. touch, accidental brushing • Failure to allow adequate gas• Inability to turn the flow – broken control knob ON stem blocking the path.
PHYSICS FLOWMETER • LOW FLOWS – • LAMINAR FLOW VISCOSITY • HIGH FLOWS • TURBULANT • DENSITY
FLOW INDICATER• RATE OF FLOW • PRESSURE DROP• Pressure drop • Frictional across constriction resistance float &• Size of annular tube wall opening • Turbulent flow• Physical properties • Drop in energy of gas • Wt float / cross sectional area
FLOW METER • Thrope tube • Narrow at bottom • Calibrated for gas at atm. Pressure, 20° C • Single, dual taper • Antistatic coating • Float • Float rest, stop • Annular space • Fluorescent
FLOAT OR BOBBIN • Nonrotating • Plumb bob, striked rotating • Ball • Indicator of constant flow • Important to monitor • Float stop • Float rest • Rib guides
PROBLEMS OFFLOWMETER ASSEMBLY• FLOWMETER • FLOAT• Inaccuracy at low • Sudden flow projection to top• Calibration with opening of• Sticking dust cylinder• Back pressure • Block outlet flow drops float to • Wrong flow meter lower position. used.
SEQUENCE OF FLOW INDICATER• Series – one flow control knob• Such that delivery of hypoxic mixture is prevented.• ASTM – O2 downstream - flow indicator – near outlet• Any separate vaporizer flow indicator should be separated by at least 10 cm.
IMPORTANCE OFDOWNSTREAM OF O2 • Downstream of oxygen prevent hypoxic mixture going to patient in case of leak in the flow indicator • Safety mechanism • Downstream leak change in quantity
MINIMUM O2 RATIO DEVICES• Pneumatic systems• Mechanical systems• Alarm systems• Oxygen ratio monitor controller & alarm• Next generation will be electronic flow measurement
OHMEDA LINK 25 SYSTEM • Pneumatic - • At least 25% of oxygen flows in the system • One of the hypoxia guard • Mechanical- linkage in O2 N2O knobs by 14 vs 29 tooth sproket
UNIDIRECTIONL CHECK VALVE • Unidirectional check valve • Between vaporizer• Positive pressure & common gas from the breathing outlet system is • Upstream of O2 transmitted to flush flow joins machine in IPPV & fresh gas flow assisted ventilation&O2 • Gas must flow flush from flowmeter • Leak not detected
PRESSURE RELIEF VALVE• Near the common • Opens at 100 cm gas outlet of H2O• To prevent high pressure from • Limits anesthesia being transmitted machine to in to machine deliver jet• To prevent high ventilation pressure being transmitted to Pt • Present in some from machine machine
VAPORIZER MOUNTING DEVICE• Located in between flowmeter device and common gas outlet• Permanent mounting• Change of vaporizer
LOW PRESSURE PIPING• Large number of connections• Subject to break or leak• Flow should not exceed above 30 ml/min at a pressure of 3KPa or 30 cm of water
COMMON GAS OUTLET• Receives gases & vapors from the machine• Outlet in most of the machines have 15 mm female slip-joint connection, with coaxial 22 mm male connection• Frequent location for leak
SAFTY MECHANISMS• Antistatic coating • Fluorescent back• Antistatic wheels of flow meter• Color coding • Master & slaves• Pin index • O2 failure alarm• DISS • Oxygen flush• Pressure guage • Pressure relief• Touch, coding, pl valve acement of flow • Unidirectional regulator check valve• Rotating bobbin • Trilene interlock with close system