Oxygen Depletion Monitor for MRI rooms
Guards against suffocation hazards due to cryogen leakage

MRI machines contain powerful super conducting magnets that are cooled by liquid helium. The storage and handling of liquid helium and liquid cryogen presents a safety hazard within the MRI environment. Helium is a colorless and odorless gas not directly detectable by humans. In the event of a cryogen leak the air and hence the oxygen in the room can be rapidly displaced by the helium or nitrogen gas thus reducing the ambient oxygen concentration and posing a suffocation asphyxiation hazard to personnel in the MRI room. For this reason it is recommended and often mandated that MRI rooms be monitored with an oxygen depletion (deficiency) monitor. The MIDAS O2 is designed for this purpose. It comprises a sensitive oxygen sensor and electronics package with a remote sensing system. The instrument must be located outside the range of the MRI magnetic field environment. The atmosphere is constantly sampled by a length of tubing that runs from within the MRI room to the instruments sampling port. The MIDAS O2 is self contained with a built in sampling pump alarm relays, and analog and digital alarm outputs. The unit is small in in size and its easy access metal chassis design makes it simple to install even when space is at a premium. The unit can be wall mounted using mounting points on the back of the chassis. An optional L bracket provides a free standing mount which can be secured to a horizontal surface. A duct adaptor is provided should it be necessary to connect the sample tube line into an air duct.

MIDAS O2 includes various power and communicationsoptoins as standard including 3 on-board relays, 4 - 20mA analog output, Modbus/ TCP Ethernet digital outputs, as well as the innovative Power over Ethernet (PoE) protocol - a single Ethernet connection for all power, control and communication requirements. It can be run as standalone alarm system or integrated with PLC and FieldBus systems.

MIDAS O2 offers lower cost of ownership benefits for increased MRI safety through a combination of extended sensor calibration periods, flexible communications architecture, and patented diagnostics that monitor sensor performance and flow control. MIDAS O2 will monitor points up to 30m (100 feet) away from the transmitter and flow rates are regulated automatically using patented control technology to ensure error free gas sensing operation.

For an MRI room, the sensor must be located outside to exclude any metals from the environment. A sampling pump draws air from the MRI zone and delivers it to the oxygen sensor. Cryogen leakage can cause rapid suffocation when concentrations are high enough to reduced oxygen concentration levels below 19.5%.

Specifications

Transmitter Dimension	(unit with Sensor) 120mm (H) x 63mm (W) x 150mm (D)	Weight: (unit with Sensor) 0.8Kg
Power Requirements	Operating Voltage 24V DC Nominal +/- 10%	Operating Voltage with Power over Ethernet (PoE): 36 - 57 VDC via PoE, 48V DC Nominal
Power Consumption	Transmitter Unit: ~ 5.0W
Outputs	Visual: Alarm, Power and Fault lights as well as back lit LCD display with all gas readings and events	Relays: 3 relays for Alarm1, Alarm 2 and Fault rated 1.0A @ 30VDC or 0.5A @125VAC; configurable NO or NC, latched or unlatched
	Analog: 2 wire isolated, 0 - 22mA, Sink or Source	Digital : Modbus / TCP Ethernet / Power over Ethernet (PoE)
	Service Port RS232C / PPP protocol
Sampling Distance	Tubing Length: Up to 30m (100 feet)	Ambient Point Monitoring: In line air filter recommended
Tubing Requirement	Exhaust Length Up to 30m (100 feet)
	Sample: 6.35mm OD (1/4”) x 3.18mm (1/8”), FEP, 30m (100 feet) maximum dependant on gas type
Operating Temperature	0˚ C (32˚ F) to 40˚ C (104˚ F)
Wiring Requirement	4-20mA/DC Power/Relays: 14 AWG Maximum	Digital: CAT 5 cable or equivalent, RJ45 connector
Gas Concentration Display & Interface	Instrument: 4-digit alphanumeric display with separate measurement units, flow rate bar graph and other icon driven indicators. 4 button membrane keypad	Remote Interface: PC / PDA Internet Browser access via Ethernet or other Bus system
Response Times	Flow Rate: 500 mL/min	Transport Time: 2 - 30 seconds maximum
Warranty	Transmitter Unit: 1 year Sensor Cartridge: 1 year standard; 2 year with extended warranty program Expected Lifetime of Pump: >2 years
Certification & Specification	European: CE marked; meets EN 50270:1999 (Type2) and EN 55011:2000 Environmental: ETL approved UL 61010B and CSA-C22.2 No. 1010.1-92 Performance: Designed to meet with UL 2075 (pending 2004) Electrical: >IEEE 802.3af-2003

Ordering Information

PART NUMBER	UNIT	PRICE
MIDAS-K-O2X	MIDAS O2X (O2) Cartridge and Transmitter Kit, includes built in wall mount and duct adapter Oxygen Range(O2): 0.2-25% v/v - default alarm 19.5%	$1799.00
MIDAS-A-032	Vertical mounting L bracket kit (The standard instrument can be wall mounted via 2 screws through the backplate of the housing - the optional L bracket provides a means of supporting the unit on a horizontal surface note that the utilities pass through the bottom of the housing)	$133.00
1283k1090	Spare Duct adapter for 1/4" O.D tubing for 4-16" round ducts, allows connection of sample line tubing thru the wall of a duct	$56.00
TB	1/4" Polypropylene tubing for sample line - 100 ft	$125.00