Blanketrol II Model 222R Hyper-Hypothermia Units Operation and Technical Manual Rev X

Symbols Temperature Set

Stop - Repair

Equipotential Ground

Water Temperature

Increasing Temperature

Silence Alarm

Temp. Set Point Indicator

Decreasing Temperature

Caution: Read Operation Instructions and Manual Before Operating

Patient Temperature

Automatic Control

Risk of Explosion: Do not use in the Presence of Flammable Anesthetics

Power Cord Holder

Danger; Risk of Electric Shock

Clean Condenser Monthly Separate collection for electrical and electronic equipment

~ AC Voltage II

Disconnect Power Before Servicing

Water Flow Indicator

Manual Control

Change Water Monthly

Fill to Strainer

Inlet Test Indicators Outlet

Clean Water Filter Quarterly

ESD Susceptibility

Monitor Only

Type B Equipment

BLANKETROL® II OPERATION/TECHNICAL MANUAL Cincinnati Sub-Zero Products, Inc., reserves the right to make equipment changes and improvements, which may not be reflected in this manual.

CAUTION Federal law restricts this device to use only on the order of a physician.

DANGER •

Notify the physician if the patient's temperature is not responding properly or does not reach the temperature prescribed in the prescribed time or if there is a change in the prescribed temperature range. Failure to inform the physician of the deviation may result in injury to the patient.

•

Do not use the BLANKETROL II system in the presence of flammable anesthetics. Risk of explosion can result.

•

Power interruption will cause the BLANKETROL II to revert to CHECK SETPOINT resulting in no therapy to the patient. Follow instructions for desired mode to resume operation. Failure to resume therapy could result in serious injury or death.

BLANKETROL®, MAXI-THERM®, MAXI-THERM LITE®, TEMP-PAD®, and PLASTIPAD® are registered trademarks of Cincinnati Sub Zero Products, Inc., Cincinnati, Ohio USA.

Manual 56230 Rev. X, M608-3368 III

CAUTION •

Use distilled water only. Do Not Use De-Ionized water.

•

Do not use alcohol. Alcohol may cause blanket deterioration.

•

Do not overfill. Overfilling may result in overflow when the water in the blanket drains back into the system when the system is turned off.

DANGER •

The repair, calibration, and servicing of the BLANKETROL II should be performed by qualified Medical Equipment Service Technicians, Certified Biomedical Electronics Technicians, or Certified Clinical Engineers familiar with good repair practices for servicing medical devices, and in accordance with instructions contained in this manual. Improper repair can result in damage to the BLANKETROL II system and patient injury.

DANGER Before returning the BLANKETROL II to patient use after repairs, the FIRST TIME SETUP/SYSTEM TEST ROUTINE in Section 2 must always be performed. Improper repair can result in damage to the BLANKETROL II system and patient injury.

IV

WARNING

•

A physician's order is required for setting blanket temperature and use of equipment. At least every 20 minutes, or as directed by physician, check patient's temperature and skin condition of areas in contact with blanket; also, check blanket water temperature. Pediatric, temperature-sensitive, patients with vascular disease, and operating room patients should be checked more frequently. Notify the physician promptly of any change in patient status in order to avoid serious injury or death.

•

The method of temperature control provided by all hyper-hypothermia units presents the danger of heating or cooling body tissues, particularly the skin, to a point where they are injured, i.e., burns or frostbite, respectively. Depending on the extent and severity of a burn, very serious and even fatal complications may arise.

•

Prevent excessive and/or prolonged tissue pressure and shearing forces, especially over bony prominences, to prevent skin damage that may result.

•

Do not place additional heat sources between the patient and blanket. Skin damage may result.

•

The area between the patient and the blanket should be kept dry to avoid injury to patient.

•

Use only 400 Series, or equivalent, probes on CSZ equipment. Failure to do this will cause incorrect temperature readings.

©

Copyright 1982, Cincinnati Sub-Zero Products, Inc. All rights reserved.

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TABLE OF CONTENTS SYMBOLS ... II TECHNICAL HELP ... 1 AUTHORIZED EUROPEAN REPRESENTATIVE: ... 1 BEFORE YOU CALL FOR SERVICE... 1 IN-WARRANTY REPAIR AND PARTS ... 1 RECEIVING INSPECTION ... 1 IMPORTANT SAFETY INFORMATION ... 1 SECTION 1. INTRODUCTION ... 2 1-0. 1-1. 1-2. 1-3. 1-4.

1-5. 1-6.

1-7. 1.8

GENERAL SAFETY PRECAUTIONS ... 2 GENERAL DESCRIPTION OF THIS MANUAL ... 2 GENERAL DESCRIPTION OF THE BLANKETROL II SYSTEM ... 3 CLINICAL APPLICATIONS ... 3 PHYSICAL DESCRIPTION OF THE BLANKETROL II UNIT ... 3 1-4.1. EXTERNAL FEATURES - FRONT VIEW ... 4 1-4.2. EXTERNAL FEATURES - RIGHT SIDE VIEW... 6 1-4.3. EXTERNAL FEATURES - REAR VIEW... 8 1-4.4. EXPANDED DESCRIPTION OF THE BLANKETROL II CONTROL PANEL... 10 REQUIRED ACCESSORIES... 12 FUNCTIONAL DESCRIPTION OF THE BLANKETROL II SYSTEM ... 12 1-6.1. HEATING SYSTEM ... 12 1-6.2. COOLING SYSTEM ... 13 1-6.3. CIRCULATING SYSTEM ... 13 1-6.4. TEMPERATURE SAFETY CONTROL SYSTEM... 13 SPECIFICATIONS OF THE BLANKETROL II UNIT ... 15 BLANKETROL II CERTIFICATIONS ... 16

SECTION 2. GENERAL PREPARATION OF THE BLANKETROL II 2-1. 2-2. 2-3.

2-4. 2-5.

SYSTEM ... 17

INTRODUCTION ... 17 UNPACKING THE SHIPMENT ... 17 FIRST TIME SET-UP/SYSTEM TEST ROUTINE ... 17 2-3.1. INSPECTING AND ARRANGING THE EQUIPMENT... 18 2-3.2. COMPLETING A SYSTEM TEST ROUTINE ... 19 UNIT AND PATIENT RELATED PRECAUTIONS... 23 PATIENT PREPARATION AND BEDSIDE CARE... 24

SECTION 3. OPERATING THE BLANKETROL II UNIT... 26 3-1. 3-2. 3-3. 3-4. 3-5. 3-6. 3-7. 3-8.

INTRODUCTION ... 26 ARRANGING THE SYSTEM COMPONENTS ... 26 OPERATING THE BLANKETROL II UNIT IN AUTOMATIC CONTROL MODE ... 28 OPERATING THE BLANKETROL II UNIT IN MANUAL CONTROL MODE... 30 OPERATING THE BLANKETROL II UNIT IN MANUAL CONTROL MODE WITH THE ADDITION OF THE PATIENT PROBE ... 32 OPERATING THE BLANKETROL II UNIT IN MONITOR ONLY MODE ... 33 CONCLUDING HYPER-HYPOTHERMIA TREATMENT... 34 STATUS DISPLAY MESSAGES... 35

SECTION 4. GENERAL MAINTENANCE OF THE BLANKETROL II SYSTEM... 38 4-1. 4-2.

4-3. 4-4.

VI

INTRODUCTION ... 38 4-1.1 TEST EQUIPMENT REQUIRED ... 39 MAINTENANCE OF THE WATER RESERVOIR... 41 4-2.1. DRAINING THE RESERVOIR ... 42 4-2.2. REPLENISHING THE RESERVOIR ... 43 MAINTENANCE OF THE WATER FILTER ... 44 MAINTENANCE OF THE CONDENSER AND GRILLE ... 44

4-5. 4-6.

4-7.

MAINTENANCE OF THE BLANKETROL II EXTERIOR ... 45 MAINTENANCE OF THE HYPER-HYPOTHERMIA BLANKETS... 45 4.6.1 PLASTIPAD REUSABLE BLANKET ... 45 MAXI-THERM , MAXI-THERM LITE, AND TEMP-PAD (DISPOSABLE) HYPER4-6.2. HYPOTHERMIA BLANKETS... 46 MAINTENANCE OF REUSABLE THERMISTOR PROBES... 46

SECTION 5. FIELD REPAIR/SERVICE OF THE BLANKETROL II UNIT ... 47 5-1. 5-2.

5-3. 5-4. 5-5. 5-6. 5-7. 5-8. 5-9. 5-10. 5-11. 5-12. 5-13 5-14. 5-15. 5-16. 5-17. 5-18.

5-19. 5-20. 5-21. 5-22.

INTRODUCTION ... 47 ACCESS TO THE INTERIOR OF THE BLANKETROL II UNIT... 50 5-2.1. REMOVING THE REAR ENCLOSURE PANEL ... 50 REPLACING THE REAR ENCLOSURE PANEL ... 50 5-2.2. 5-2.3. REMOVING THE TOP OF THE UNIT ... 51 5-2.4. DISCONNECTING THE CABLES FROM THE POWER SUPPLY BOARD... 51 DISCONNECTING THE CABLES FROM THE MICROPROCESSOR BOARD... 52 5-2.5. 5-2.6. EXTENDING THE FRONT STORAGE DRAWER... 53 REPLACEMENT OF THE HEATER ... 53 REPLACEMENT OF THE WATER FILTER ASSEMBLY ... 54 REPLACEMENT OF THE PUMP HOUSING ... 54 REPLACEMENT OF THE PUMP MOTOR ... 55 REPLACEMENT OF THE WATER TEMPERATURE SENSOR ... 56 REPLACEMENT OF THE UPPER AND/OR LOWER WATER MANIFOLDS... 57 REPLACEMENT OF THE COMPRESSOR STARTING CAPACITOR, THE ... 59 OVERLOAD PROTECTOR, AND/OR THE COMPRESSOR RELAY ... 59 REPLACEMENT OF THE THERMAL DISC FOR THE TEMPERATURE SAFETY DEVICE... 59 REPLACEMENT OR CLEANING OF THE WATER FLOW INDICATOR ASSEMBLY... 59 REPLACEMENT OF THE ON/OFF POWER SWITCH ... 61 REPLACEMENT OF THE CELSIUS/FAHRENHEIT SELECTOR SWITCH... 61 REPLACEMENT OF A THREE POLE POWER RELAY ... 62 REPLACEMENT OF THE WATER LEVEL SENSOR ASSEMBLY ... 62 REPLACEMENT OF THE POWER SUPPLY BOARD... 63 REPLACEMENT OF THE MICROPROCESSOR BOARD AND/OR THE CONTROL PANEL ... 64 LEAKAGE CURRENT... 65 5-18.1. ARRANGING THE EQUIPMENT ... 65 5-18.2. TAKING MEASUREMENTS IN NORMAL POLARITY ... 65 5-18.3. TAKING MEASUREMENTS IN REVERSE POLARITY... 66 REFRIGERANT CHECK ... 66 LOW LIMIT SAFETIES CHECK ... 67 HIGH LIMIT SAFETIES CHECK ... 68 TROUBLESHOOTING GUIDE ... 70

SECTION 6. PARTS INFORMATION ... 81 6-1. 6-2. 6-3. 6-4. 6-5.

INTRODUCTION ... 81 ORDERING INFORMATION FOR REPLACEMENT PARTS... 81 RECOMMENDED REPLACEMENT PARTS INVENTORY ... 81 RETURNING PARTS UNDER WARRANTY ... 82 SHIPPING PARTS ... 82

VII

ILLUSTRATIONS/SCHEDULES/PARTS LISTS Figure 1-1 Figure 1-2 Figure 1-3 Figure 1-4.A. Figure 1-4.B. Figure 4-1 Figure 4-2 Figure 5-1 Figure 6-1 Figure 6-2 Figure 6-3 Figure 6-4 Figure 6-5 Figure 6-5A Figure 6-5B Figure 6-5C Figure 6-10 Figure 6-11 Figure 6-12

VIII

BLANKETROL II Unit - Front View... 5 BLANKETROL II Unit - Right Side View... 7 BLANKETROL II Unit - Rear View ... 9 BLANKETROL II Unit - Control Panel ... 11 BLANKETROL II Unit - Control Panel ... 11 Maintenance Schedule ... 38 Maintenance Checklist ... 40 BLANKETROL II Unit - Exposed Rear View ... 49 Parts List A ... 83 BLANKETROL II Unit - Internal Exploded Front View... 84 Parts List B ... 85,86 BLANKETROL II Unit - Internal Exploded Rear View ... 87 Electrical Wiring Diagram-115V... 88 Electrical Wiring Diagram-230V... 89 Electrical Wiring Diagram-240V... 90 Electrical Wiring Diagram-100V... 91 Water Circulation Diagram ... 92 Refrigeration Flow Diagram... 93 BLANKETROL II System Equipment & Accessories ...94

TECHNICAL HELP United States and Canada Cincinnati Sub-Zero Products, Inc. 12011 Mosteller Road Cincinnati, OH 45241

Telephone Toll Free Fax

1-513-772-8810 1-800-989-7373 1-513-772-9119

AUTHORIZED EUROPEAN REPRESENTATIVE: CEpartner4U Telephone + 31 (0) 6-516.536.26 Esdoorlnaan 13, 3951 DB Maarn. The Netherlands BEFORE YOU CALL FOR SERVICE... To help us better serve you, please have the serial number of your BLANKETROL II unit ready when you call for parts or service. IN-WARRANTY REPAIR AND PARTS All parts on your BLANKETROL II unit are covered by a two-year warranty. To return defective parts or units, first obtain a Returned Materials Authorization (RMA) number from our Medical Technical Service department.

RECEIVING INSPECTION After unpacking the BLANKETROL II System, be sure to inspect the system for concealed damage. Retain all packing material and carefully describe or photograph any damage. Notify the carrier at once and ask for an inspection (in writing). Failure to do this within 15 days may result in loss of claim. Do not return the equipment to Cincinnati Sub-Zero. Call our Medical Technical Service department for further instructions.

IMPORTANT SAFETY INFORMATION Refer to this manual for instructions and caregiver information. Read and understand all precautionary information before using, prescribing, or servicing the BLANKETROL II unit.

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

SECTION 1. INTRODUCTION 1-0.

GENERAL SAFETY PRECAUTIONS

To provide the patient maximum safety during the use of the BLANKETROL II hyperhypothermia system, a thorough knowledge and understanding of the system, and its correct application and operating use are required. Each person who is responsible for use or direction of use of the system, such as physicians, nurses, technicians and operators must read and understand this operating manual and all precautions and warnings prior to use. It is recommended this manual be reviewed at least semi-annually as a refresher to safe operation and application. 1-1.

GENERAL DESCRIPTION OF THIS MANUAL

This manual describes the operation, maintenance, and service of the CSZ BLANKETROL II hyper-hypothermia system. Section One describes the physical and functional characteristics of the BLANKETROL II System. Section Two describes how to prepare the BLANKETROL II unit for general use. Section Three describes how to operate the unit in the Manual Control Mode, Automatic Control Mode, and Monitor Only Mode. Section Four describes the regular maintenance of the BLANKETROL II unit. Section Five describes Field Repair and Service of the BLANKETROL II unit. Section Six is a Troubleshooting Guide and Section Seven outlines parts information. This manual is prepared for professional personnel who use the equipment for patient care. It is also intended for technicians and service personnel who are responsible for maintaining the equipment.

2

INTRODUCTION

1-2.

BLANKETROL II, 222R OPERATION MANUAL

GENERAL DESCRIPTION OF THE BLANKETROL II SYSTEM

The CSZ BLANKETROL II (Model 222R) Hyper-Hypothermia System is used to lower or to raise a patient's temperature and/or maintain a desired patient temperature through conductive heat transfer. The CSZ BLANKETROL II unit is composed of a heater, a compressor, a circulating pump, and a microprocessor. This unit requires no field adjustments or calibrations in order to maintain the precise measurement of temperature and temperature limits. Water is heated or cooled and pumped from the unit to a blanket. The blanket* rests under and/or on top of the patient and is designed so that the water circulates through the blanket and returns to the unit. If cooled water is circulated through the blanket, the desired effect is to reduce the patient's temperature. If warmed water is circulated through the blanket, the desired effect is to elevate the patient's temperature. The BLANKETROL II unit can be set so that it operates based on the temperature of the circulating water (Manual Control) or it can be set so that it operates based on the temperature of the patient (Automatic Control). * The recommended blanket(s) for use is described in Section (1-5.)

1-3.

CLINICAL APPLICATIONS

The BLANKETROL II unit is used primarily in hospital Intensive and Coronary Care Units, in Operating, Recovery and Emergency Rooms, in Burn Units, and on Medical/Surgical floors. This hyper-hypothermia system has been used with adult and pediatric patients to produce normothermia by lowering a patient's elevated temperature or raising a patient's sub-normal temperature. It can also be utilized to maintain normal body temperature (normothermia) during surgical procedures. Surgically, this system has been used to produce moderate to profound hypothermia for such procedures as amputations, cardiopulmonary by-pass surgery, vascular surgery, and intracranial surgery. Medically this system has been used to decrease the rate of circulation, to reduce intracranial pressure, to control cerebral edema, and to reduce oxygen requirements. This system has also been used in the treatment of burns, shock, cardiac arrest, and gastrointestinal hemorrhage.

1-4.

PHYSICAL DESCRIPTION OF THE BLANKETROL II UNIT

See Section 1.7

3

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

1-4.1. EXTERNAL FEATURES - FRONT VIEW The external features in Figure (1-1) of the BLANKETROL II unit are described as follows: A.

The control panel is composed of pressure sensitive touch switches and four LED displays. An expanded description of the control panel is presented in Section (1-4.4.).

B.

The operating instructions are printed directly below the control panel. This layout is designed to increase the operator's efficient use of the unit.

C.

The power switch is a bevel rocker switch labeled ON at the top and OFF at the bottom. The switch lights up green when ON. A circuit breaker is built-in the switch to protect against overload conditions.

D.

The storage drawer tilts out from the top to provide storage space for items such as probes, connector cables, connecting hoses, the drain hose, and the Operator's Manual.

E.

The grille permits air to be drawn into the unit and pass over the condenser. The air is then discharged through the bottom of the unit. The grille should be kept from being blocked by being cleaned regularly as described in Section (4-4.).

F.

The protective bumper guard surrounds the lower edge of the unit and protects the unit as well as the walls.

G.

Four conductive, swivel casters are specially designed to permit the unit to move easily and to prevent it from tipping.

H.

The Celsius/Fahrenheit selector switch, abbreviated C/F, is a rocker switch that permits the operator to select the measurement scale, Celsius or Fahrenheit, by which the unit functions. Celsius is in the down position and Fahrenheit is in the up position. NOTE: The C/F switch is not available on 230V and 240V versions.

I.

4

The water fill opening is where the operator pours distilled water to fill the reservoir.

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

FIGURE 1-1. BLANKETROL II, FRONT VIEW

5

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

1-4.2. EXTERNAL FEATURES - RIGHT SIDE VIEW The external features in Figure (1-2) of the BLANKETROL II unit are described as follows: A.

The water flow indicator is a paddle wheel immersed in the path of the circulating water with a window to the outside. As water is circulated through the system, it must pass over the paddle wheel causing it to spin (like a pinwheel). The water flow indicator provides a visual display of the general rate at which the water is circulating. For example, if the unit is circulating water but the connecting hose is pinched, the circulation of the water is restricted. The change in water flow decreases the speed of the paddle wheel. A total obstruction of the water path will cause the paddle wheel to stop completely.

6

B.

The recessed handle permits the operator to grip the unit when moving it.

C.

The four capped screws on the right and left side of the unit secure the top to the base.

D.

The patient probe jack is where the 400 Series probe is connected to the unit. Only one patient probe can be connected at a time.

E.

Three female, quick-disconnect return couplings on the top row are designed for water to flow in when the male coupling of the connecting hose is attached.

F.

The three male quick-disconnect outlet couplings on the bottom row are designed for water to flow out when the female coupling of the connecting hose is attached.

G.

The power cord with a hospital-grade 3-prong plug should only be inserted into a properly grounded hospital grade receptacle for 100/115 VAC units and 230/240 VAC units. Electrical Specifications are described in Section (1-7.).

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

FIGURE 1-2 BLANKETROL II, RIGHT SIDE VIEW

7

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

1-4.3. EXTERNAL FEATURES - REAR VIEW The external features in Figure (1-3) of the BLANKETROL II unit are described as follows:

8

A.

The specification label outlines the BLANKETROL II unit's electrical requirements.

B.

The maintenance label outlines the periodic checks for the BLANKETROL II unit.

C.

Two air vents provide air circulation for the microprocessor.

D.

The nylon strap is used to secure and store the coiled power cord when not in use.

E.

The rear enclosure panel secured with four screws provides access to the interior. The panel is removed to perform maintenance, repair, or replacement of components.

F.

The serial number label is permanently attached and located along the bottom of the unit on top of the bumper guard.

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

FIGURE 1-3, BLANKETROL II, REAR VIEW

9

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

1-4.4. EXPANDED DESCRIPTION OF THE BLANKETROL II CONTROL PANEL The control panel as shown in Figure 1-4.A for 100/115 Volt and 1-4.B for 230/240 Volt is composed of pressure sensitive touch switches and LED displays. The control panel is divided into the following Sections:

10

A.

The digital display labeled BLANKET/WATER shows the actual temperature of the circulating water.

B.

The MANUAL CONTROL touch switch is used to activate the unit so that operation is based on the temperature of the circulating water relative to the Set point temperature.

C.

The digital display labeled SETPOINT shows the desired temperature of the water or the patient as set by the operator.

D.

The TEMP SET switch and the Up and Down arrow switches are used to set the Set point display. The amber arrow on the left of the Set point display, the amber arrow on the right of the Set point display, the Celsius, and Fahrenheit. Indicator shows mode and desired temperature scale.

E.

The digital display, labeled PATIENT, shows the actual temperature of the patient.

F.

The AUTO CONTROL switch is used to activate the unit so that operation is based on the temperature of the patient relative to the Set point temperature.

G.

The two switches labeled TEST INDICATORS and SILENCE ALARM are used to confirm that all the indicators on the control panel are working and to silence the alarm in certain conditions.

H.

The display labeled STATUS reports the status of the unit and/or indicates changes that the operator should make. The possible status displays are listed in Section (3-8.). Below the Status display are the three LEDs colored amber, green, and amber that light up depending on whether the unit is cooling, at setpoint, or heating.

I.

A REMOVE FROM SERVICE indicator is located below the LED and is visible only if the unit malfunctions in a manner that could be dangerous to the patient and is not Operator Correctable.

J.

The MONITOR ONLY switch is used to set the unit to monitor the temperature of the patient without heating, cooling or circulating the water.

INTRODUCTION

BLANKETROL II, 222R OPERATION MANUAL

FIGURE 1-4.A., BLANKETROL II, CONTROL PANEL, 115 VAC UNITS

FIGURE 1-4.B., BLANKETROL II, CONTROL PANEL, 230-240 VAC UNITS

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INTRODUCTION

1-5.

BLANKETROL II, 222R OPERATION MANUAL

REQUIRED ACCESSORIES

Operation of the BLANKETROL II unit requires the use of the blanket(s) designed to circulate warm or cool distilled water, a connecting hose with quick-disconnect male and female couplings, and a 400 Series thermistor probe (if Automatic Control Mode is to be utilized). BLANKETROL II System Equipment and accessories are listed in on the last page of this manual. 1-6.

FUNCTIONAL DESCRIPTION OF THE BLANKETROL II SYSTEM

In the Manual Control Mode, the operator sets the desired temperature of the circulating water. The unit either heats or cools the water to reach the desired setpoint temperature. The water circulates through the blanket and either raises or lowers the temperature of the patient. In this case, the patient's temperature must be closely monitored. There is no constant relationship between the temperature of the circulating fluid and the temperature of the patient or the change in temperature of the patient. In the Automatic Control Mode, the operator sets the desired temperature of the patient. In addition, the operator must attach a 400 Series probe in or to the patient. The probe is then inserted into the BLANKETROL II unit. The probe is used to measure the actual temperature of the patient and this measurement is then compared with the desired Setpoint temperature by the unit's microprocessor. If the actual patient temperature is lower than the desired patient temperature, the BLANKETROL II unit heats the circulating water so that the temperature of the patient is elevated to reach the desired Setpoint. At Setpoint, the unit continues to circulate the water but the heater ceases to operate. When the patient's temperature falls outside the Setpoint range, the heater/compressor resumes operation, heating/cooling the water until the patient's temperature is once again at Setpoint. If the actual temperature is higher than the desired patient temperature, the BLANKETROL II unit cools the circulating water so that the temperature of the patient decreases to the desired Setpoint temperature. At Setpoint, the unit continues to circulate the water, but the compressor stops. When the patient's temperature falls outside the Setpoint range, the compressor/heater resumes operation, cooling/heating the water until the patient's temperature is once again at Setpoint. In addition, the BLANKETROL II unit can be set to operate in a Monitor Only Mode. In this mode, the 400 Series probe is attached to or inserted into the patient and is connected to the unit. The operator then sets the BLANKETROL II unit to monitor and display the patient's actual temperature. In this mode, the unit does not heat, cool, or circulate the water. 1-6.1. HEATING SYSTEM The BLANKETROL II heating system consists of an immersion heater, water temperature control, and three high temperature safety devices. Temperature ranges are described in Section (1-6.4.). The immersion heater is located in the circulating reservoir. The water circulating in the reservoir flows around the immersion heater and is warmed. The heating system is operational in the Manual Control or Automatic Control Modes whenever the control system calls for an increase in the temperature of the circulating water. It is important to

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