Models EV4542 and EV4543 Instruction Manual

Collet terminal (RED) For connecting the indifferent electrode lead (positive)

Collet terminal (BLACK) For connecting the active electrode lead (negative)

Function Indicators Indicate pacing, sensing and battery

Output Adjusts the voltage of the pacing pulse

Sensitivity Adjusts the ‘R’ –wave sensing level in the demand mode

Rate Adjusts the frequency of pacing pulses

On/Off switch with x1/x3 rate position

Demand/Asynchronous Select mode of operation

Hinged Plastic Cover

Key to MINIATURE Pacemaker Controls and Features Figure 1

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CONTENTS

1.

2.

3.

4. 5. 6.

7. 8.

9. 10. 11.

System familiarization 1.1 Introduction 1.2 Parts supplied 1.3 Specifications 1.4 Indications and contraindications Features and controls 2.1 Function indicators 2.1.1 Pacing 2.1.2 Sensing 2.1.3 Battery replacement 2.1.4 Interference 2.2 Controls 2.2.1 Sensitivity 2.2.2 Output 2.2.3 Rate 2.2.4 Demand/asynchronous switch 2.2.5 On (X1)/off and X3 switch 2.3 Collet terminals Operating instructions 3.1 Lead placement 3.2 Connecting the lead to the pacemaker 3.3 Determination of pacing threshold 3.4 Determination of sensing threshold Precautions Equipment care Troubleshooting 6.1 Interference 6.2 High rate protection 6.3 Battery replacement 6.4 Miscellaneous clinical problems Accessories Miscellaneous 8.1 Additional information 8.2 Limited warranty Storage Use and care of the extension cable Classifications / certifications

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4 4 5 6 7 8 8

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9 10 10 10 11 12 13 15 16 16 18 18 19 20 21 21 22 23 24 25

Illustrations

Key to MINIATURE pacemaker controls

1

Pace, sense and battery level indicator LEDs

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Connecting the lead to the pacemaker

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Relationship of selected rate and interference rate

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Changing the battery

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Connecting the extension cable

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3

1.

System Familiarization

1.1

Introduction The Pace Medical MINIATURE Temporary Pacemaker, an external cardiac pacemaker with internal power source, offers short-term pacing support for a patient with myocardial infarction or temporary heart block. The MINIATURE pacemaker operates in either the R-wave inhibited (demand) or the asynchronous mode with rate continuously variable within the range of 30 - 150 ppm when the switch is moved from off to on. The EV4543 has two ranges of operation, selected by an X1 and an X3 rate multiplier switch. In X1, the unit operates in the same manner as the EV4542, but in X3 the unit operates in the asynchronous mode only for high rate pacing up to 450ppm. Selection of the X3 rate position will automatically change the unit to asynchronous mode and will override the demand mode of the demand/async switch. WARNING:

THE X3 POSITION IS FOR SPECIAL SHORTTERM HIGH RATE ATRIAL PACING ONLY.

To prevent accidental selection of high rate atrial pacing, the switch knob must be lifted before it can be turned to the X3 position. The hinged, transparent cover will not fully close during high rate atrial pacing. The output and sensitivity control scales are expanded at the lower settings to facilitate approximate threshold measurement. In the presence of an excessive level of electrical interference (EMI), the pacemaker will automatically switch from the demand mode to a temporary asynchronous pacing mode approximately 25% higher than the selected rate. Normal function is resumed when the level of interference is reduced below the level of detection or stops completely. Should an electronic component failure occur in the unit, the maximum high asynchronous rate is limited to 200ppm in model EV4542 or in the model EV4543 in the X1 mode. Model EV4543 operated in the X3 mode is limited to 500ppm.

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1.2

Parts supplied MINIATURE Temporary Cardiac Pacemaker One 9 volt alkaline battery (IEC Type 6LR61) Two straps Instruction manual Extension cable Carrying case

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1.3

Specifications (@ 20°C ± 2°C and 500 Ohms ± 1%) Mode of Operation

R-wave inhibited or asynchronous

Voltage output (continuously variable) Accuracy ± 0.05V or ± 20% Pulse rate (continuously variable) Accuracy ± 5%

0.2 - 12 V

30 - 150 ppm

Pulse duration (fixed) Accuracy ± 0.15 ms

1.5ms

Interference rate (6 Hz and above) Inhibit sensitivity (cont. var.) Accuracy ± 30%

Selected rate +25% Calibrated for +1.0 - +12mV

Refractory period (after a stimulus) Accuracy ± 30 ms

330 ms

Refractory period (after a sensed event) Accuracy ± 15 ms

150 ms

Dimensions

76mm x 145mm x 33mm

Weight

280 g or 9.8 oz.

Recommended conditions for: Operation: +10°C (+50°F) to +40°C (+104°F); RH 30% to 70% Transport/Storage: -20°C (-4°F) to +60°C (+140°F); RH less than 85% Exceeding the transport and storage temperature range may result in damage to a Model EV4543 or EV4542.

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1.4

Indications and Contraindications The MINIATURE Temporary Pacemaker may be used in any clinical situation in which the use of a temporary pacemaker on a patient provides therapeutic or diagnostic value, or serves a prophylactic purpose. Specifically, indications for temporary pacemakers include, but are not limited to, the following: intermittent or complete heart block associated with asystole or bradycardia, symptomatic sinus bradycardia, surgically-induced heart block and heart block accompanying an acute myocardial infarction. There are no known contraindications to the use of temporary cardiac pacing as a therapeutic or prophylactic modality. Nevertheless, certain relative contraindications may exist in any given patient. Among others, the application of asynchronous pacing in competition with an intrinsic rhythm may provoke arrhythmias in electrically unstable individuals. CAUTION: When clinically indicated, supplemental monitoring of a patient should be considered during temporary cardiac pacing.

WARNINGS A MINIATURE pacemaker which has been subjected to conditions of transport or storage at temperatures below 10°C (50°F) or above 40°C (104°F), should be allowed to sit at room temperature (about 20°C or 68°F) for an hour before being placed in use on a patient. Before handling an external pulse generator, patient cable(s), or indwelling lead(s), steps should be taken to equalize the electrostatic potential between the user and the patient; e.g. by touching the patient at a site remote to the pacing lead. Continuous ECG monitoring is necessary prior to pacing, during any pacing procedure, and in the immediate post-operative phase. Equipment for defibrillation, I.V. infusion, endotrachael intubation and oxygen administration must be immediately available.

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2.

Features and controls

2.1

Function indicators Light Emitting Diodes (LEDs) are used to indicate pacing, sensing, when the battery should be replaced, and the presence of detected interference.

2.1.1

Pacing This light flashes once for every pulse delivered by the pacemaker in either the demand or asynchronous mode.

2.1.2

Sensing This light flashes once for every sensed spontaneous R-wave in the demand mode only.

2.1.3

Battery replacement This light flashes simultaneously with the flashing of the Sense or Pace light to indicate good battery condition. As the battery nears depletion, the Battery light will become less visible. IN THIS CONDITION, THE UNIT WILL CONTINUE TO PACE NORMALLY, BUT THE BATTERY SHOULD BE REPLACED AS SOON AS POSSIBLE.

2.1.4

Interference If the unit is in the presence of detected interference; i.e. a signal repeating more frequently than 6Hz, both the Sense and Pace lights will flash. The Sense light is flashing in response to the interference signal. The Pace light is flashing to indicate continued pacing in an asynchronous mode at a 25% increase from the rate indicated by the rate setting. Figure 2 8

2.2

Controls All controls are located on the face of the pacemaker and protected by a hinged transparent cover.

2.2.1

are

Sensitivity This control adjusts the R-wave sensing level. It is continuously variable from +1.0 to +12 mV and is ineffective when the demand/async switch is set to async or when the rate multiplier switch on the EV4543 is set to X3.

2.2.2

Output This control adjusts the amplitude of the pacing pulse over the calibrated range of 0.5 to 20 milliamperes or 0.2 to 12 volts.

2.2.3

Rate This control adjusts the frequency at which pacing pulses are generated over the continuously variable range of 30 to 150 ppm. Model EV4543 has two switched ranges: X1 provides a pacing range of 30 - 150ppm and X3 provides a pacing range of 90450ppm. All rates are continuously variable. The X1/OFF/X3 rate switch in the model EV4543 must be lifted before turning to the X3 rate position. Selection of the X3 position overrides the demand mode of the demand/async switch. WARNING: For special short-term high rate atrial pacing only.

2.2.4

Demand/Asynchronous switch Selects the mode of operation.

2.2.5

On/off switch Switches the pacemaker on and off. In devices having the rate tripler feature, this switch is also used to switch from normal rate (X1) to triple the set rate (X3).

2.3

Collet terminals Accepts unipolar or bipolar leads with connector pins from 0.25 2mm in diameter.

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3.

Operating instructions

3.1

Lead placement When positioning the lead in the heart, it is recommended that the intracardiac ECG be monitored so that S-T segment elevation, indicating contact with the myocardium and impaction, can be noted.

3.2

Connecting the lead to the pacemaker Switch the pacemaker off. With bipolar, transvenous electrodes or leads where only one electrode is in contact with the myocardium, connect the proximal or skin electrode to the indifferent (+) red terminal and the distal or contacting electrode to the active (–) black terminal (with heartwires in a bipolar configuration, connect one lead to the indifferent (+) red terminal and one lead to the active (–) black terminal) by the following method.

Connecting the Lead to the Pacemaker Figure 3 Twist the terminal caps approximately three full turns counterclockwise, as illustrated. Push the lead connector pins into the end of the collet terminals and tighten by twisting the caps clockwise until they are just finger-tight. Do not over-tighten. WARNING: When handling indwelling leads, the connector pins or exposed metal should not be touched or allowed to come into contact with electrically conductive or wet surfaces.

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3.3

Determination of pacing threshold a)

Set the pacemaker on/off switch to off (taking any special requirements of the patient into account).

b)

Set the output control to 4V.

c)

Set the pulse rate control to a value higher than the patient's spontaneous rate.

d)

Select the desired pacing mode, demand or async and set the on/off switch to on (X1). The function indicator will show that pacing pulses are being generated at the preset rate.

e)

Turn the output control counterclockwise until cardiac stimulation ceases and then slowly turn the control clockwise until pacing resumes. Note the stimulation threshold.

f)

For reliable capture, increase the output control to a value three times the stimulation threshold. If necessary, readjust the pulse rate control to the minimum pacing rate required for the patient.

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3.4

Determination of sensing threshold To ensure reliable pacemaker detection of the patient's R-wave, the sensitivity level should be preset as follows: a)

Ensure the pacemaker is switched off (taking any special requirements of the patient into account).

b)

Set the demand/async switch to demand.

c)

Set the rate control to a value below the patient's spontaneous rate.

d)

Set the output control fully counterclockwise to 0.2V.

e)

Set the sensitivity control fully clockwise to 1.0 mV.

f)

Set the on/off switch to on (X1).

g)

Turn the sensitivity control counterclockwise until the sense light stops flashing. When this occurs, note the sensitivity setting.

h)

For reliable R-wave detection, increase the sensitivity threefold; ie. if noted setting is 3 mV, the recommended setting is 1 mV.

i)

Increase the pacing rate control to the desired level and the output control to three times the pacing threshold.

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4.

Precautions

The controls on the Pace Medical MINIATURE Temporary Cardiac Pacemaker should be operated only by qualified medical personnel. The MINIATURE temporary cardiac pacemaker is protected from damage caused by defibrillatory discharges, but care should be exercised in the placing of defibrillator paddles well away from the pacing leads. Great care should be exercised when using diathermy in association with any cardiac pacing system. Adequate monitoring must be used. Line-powered monitoring equipment should be avoided when pacing, since even minute leakage currents flowing through the heart may cause ventricular fibrillation. If line-powered equip-ment is used, the manufacturer of the equipment, or person(s) responsible for safety within your organization should be consulted on the safest method of connection. The MINIATURE pacemaker described in this information manual is not waterproof and it must not be immersed in cold sterilizing solutions. Additionally, it must not be sterilized using steam autoclaving or gamma irradiation techniques. The MINIATURE pacemaker is a life-support device. Section 6 of this manual describes the routine for battery maintenance. This is the only recommended user-serviceable item. In general, it is recommended that repair operations be performed by the specially-trained technicians of Pace Medical, Inc. When in routine use, it is recommended that calibration be checked at yearly intervals.

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CAUTION: The control knobs are individually calibrated. The pacemaker will need to be recalibrated if a knob is removed for any reason (see Section 8 for Warranty limitations).

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5.

Equipment care

Isopropanol or a dilute solution of a mild, non-abrasive detergent and water applied with a soft cloth may be used to clean the MINIATURE Temporary Cardiac Pacemaker. A MINIATURE must NOT be immersed in a cleaning solution. Ethylene oxide may be used to sterilize the MINIATURE. The temperature is typically 50°C (122°F) and the relative humidity should be 50 - 55%. The battery should be removed before sterilization and a new battery installed afterwards. The MINIATURE pacemaker must not be sterilized by steam autoclaving or irradiation. NOTE: The MINIATURE pacemaker and its extension cable should be routinely inspected for signs of physical damage or contamination, particularly damage or contamination that may have a detrimental effect on the electrical isolation properties of these devices. If such damage or contamination is identified, the pacemaker should be returned to the Company for repair. The extension cable should be promptly replaced. See sections 7 and 8 of this instruction manual.

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6.

Troubleshooting

6.1

Interference The MINIATURE pacemaker is designed to reject interference frequencies outside of the R-wave bandpass. Detected signals which repeat with a frequency of 6Hz or greater will cause reversion to the interference mode. When operating in the demand mode, an excessive level of electrical interference, for example, from diathermy or microwave ovens, will cause the pacemaker to switch automatically to asynchronous pacing at nominally 25% higher than that set on the rate control and both the sense and pace lights will flash. Normal function is resumed when the level of interference is sufficiently reduced. The typical relationship between the selected pacing rate and the pacing rate when excessive electrical interference is present, is illustrated below in Figure 4.

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Figure 4 17

6.2

High rate protection Should an electronic component failure occur in the unit, the maximum high asynchronous rate is limited to 200 ppm, unless the unit is an X3 being operated in its rapid atrial pacing mode.

6.3

Battery depletion and replacement All MINIATURE pacemakers are designed to operate on 9V alkaline batteries (IEC type 6LR61). Spare batteries should be kept available at all times. It is recommended that a new battery be used with each patient. A single, fresh 9V battery will typically last approximately thirty (30) days. Battery depletion is shown by a reduced visibility of the battery light during sensing or pacing. When this occurs, the battery should be replaced without delay even though the MINIATURE pacemaker will continue to operate for at least 24 additional hours. Although the pacemaker will continue to function for 10 seconds after battery removal, it is recommended that batteries not be changed while the pacemaker is in use on a patient. By temporarily substituting another unit, a battery change can be carried out without risk that a patient may accidently be left without pacing support; e.g. if a battery is dropped. To change the battery, push the cover up over the battery compartment, as illustrated below, remove the battery and disengage the connector. Ensure that the contact terminals are clean. Fit the connector to the new battery, observing the correct polarity and replace the battery and cover. As an additional safety precaution, the battery and contact terminals should be checked for corrosion at regular intervals.

Figure 5

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6.4

Miscellaneous clinical problems Additional minor device operating problems: A failure to tighten the connector collets securely may lead to intermittent pacing and/or sensing. Improperly set output and/or sensitivity controls may lead to the appearance of intermittent or complete failure to pace or sense. Inappropriate asynchronous operation may be due entirely to the device being switched to asynchronous mode, or as noted earlier, interference from EMI. These normal and minor pacing complications should be considered prior to concluding that a more serious device malfunction is occurring. Repair, if needed, should be referred to a qualified biomedical technician or equivalent, or to Pace Medical, Inc.

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