General Questions

Q: How do I find out the Serial Number of the EPS320 Cardiac Stimulator?

A: The Serial Number can be found on the rear of the Stimulus Generator Unit MP3008 - in the right hand bottom. It will be in the form of '0675'.

Q: Where do I find the Software Version?

A: Select Help (hotkey 'h') and choose item "About EPS320'.

Q: Where can I get a soft copy of the EPS320 User Instruction Manual?

A: Click this link to access all Micropace product Manuals.

Q: Does Micropace software come in languages other than English?

A: The Micropace EPS320 Cardiac Stimulator can be set to display its GUI (including help files) in the following languages:

English, German, French, Italian and Spanish.

Corresponding User Instruction Manuals are included on a CD-ROM or may be downloaded.

Q: Where can I get the Micropace spare parts and product catalogue and other support documents?

A: Micropace catalogues are available to its distributors - login to access the documents.

Or for its customers, from the product catalogues page.

Q: Does the EPS320 Cardiac Stimulator run on batteries?

A: The EPS320 operates indefinitely from mains power.

The battery is used only as a backup in case of mains power failure and supplies power only to the Stimulus Generator Unit, which provides simple temporary pacemaker-type function. This backup battery lasts 2hrs, which includes 10 min after activation of low battery alarm.

Note that the EPS320 is a diagnostic and not a life support device, it must be used only if a temporary pacing box is available, and pacemaker dependent patients must be paced by a temporary pacing box as soon as possible.

Q: What is the longest stimulus extension cable that is provided?

A: Longest Stimulus extension cable length is 17m, however such length must be installed with extreme caution and be tested by biomedical engineers for compliance with IEC60601-1, especially mains-applied single fault leakage current to ground.

There may also be interference to ECG trace displayed on the stimulator and more importantly possibly to the paced bipole IECG displayed in the EP recorder - required to be displayed in certain procedures such as VT entrainment.

For long lengths, it is better to locate the Stimulus Generator Unit, SGU (MP3008) under the patient bed next to the amplifier and run the serial cable from the SGU to the Bona PC in the control room. The drawback of this configuration is that the SGU under the bed is less accessible if you ever need to use its front panel for Manual Backup pacing in case of power or PC failure. You also need to have access to a power point under the bed for the SGU power supply.


Hardware Questions

Q: What should I do when my Bona PC ON Button gets stucked?

A: This is a known problem of premature button wear with earlier Bona Light PC housing designs.

  1. As an interim measure, extract the button with a small screwdriver or paper clip and then you may leave PC ON all the time and just exit software when not in use - the EPS320 Cardiac Stimulator will go into a low power mode after a period of time. To reactivate just press any key on screen or touch Screen.
  2. Contact Micropace - to obtain a new housing or new PC as required.

Q: What should I do when the External Power supply LED lit orange, despite Power Switch being turned On?

A: Orange light indicates external power connected but SGU turned Off. Replace power switch cable assembly (MP3200).

Q: What should I do if I need a replacement battery for the EPS320 Cardiac Stimulator?

A: The EPS320 contains two batteries:

  1. A 12V 2.4 Ah sealed lead acid battery for SGU backup power in case of mains power failure. Expected life is 4 years; battery failure causes a warning on SGU power-on self test.
    Order Micropace Part No. MP3209 or purchase Genesis / Yasua NP2.3-112-FR sealed lead acid battery, from Farnell - Part Number: 299 390. Contact Micropace for replacement instructions.
  2. A 9V LiMg PP3 style battery in the Emergency Fixed Rate Pacing circuit. Expected battery shelf life is 10 years. Order Ultralife U9VL, 9V lithium manganese PP3 style battery.

Q: Is there a calibration procedure for the EPS320 Cardiac Stimulator? 

A: Yes. It is only available to distributors and agents, register to gain access or login to obtain the EPS320 SGU Field Calibration Procedure document.


Software Questions

Q: What should I do if I want to copy EPS320 Cardiac Stimulator configuration from one machine to multiple others in other labs?

A: Prerequisite is software version 3.20.09 (SR3) and the following are simple instructions to save user-settings and protocols from one Micropace and into another that contains the same software versions.

Verify that software version on Source and Target machines are the same. Select Help menu with 'h' and select '9'. About the EPS320'; note that incorrect software version will cause target machine not to function.

Using a Sandisk Cruzer Micro or Cruzer Mini 256Mb or 512Mb USB Flash Drive ( the only compatible ones):
On the source computer:

  1. Switch off the Bona PC if currently on.
  2. Insert the USB Flash Drive to the front USB port of the Bona PC.
  3. Power up the PC, on observation of "Verifying DMI Pool Data........." press F5 (bypass autoexec & config files) on the keyboard. This will bring you to C prompt. (C:\>) (to prevent stim3 from launching)
  4. Type "copy c:\stim\stim.cfg d: /v" (without quotes) (If there is already a file called stim.cfg on the USB flash drive, it will prompt you whether to overwrite file - answer Y)
  5. Unplug USB Flash drive from PCOn destination computer.
  6. Follow steps 1 to 3 above.
  7. Type "copy d:\stim.cfg c:\stim /v"; on prompt to overwrite, press Y.
  8. Type "copy c:\stim\ c:\autoexec.bat /v"; on prompt tooverwrite, press Y.
  9. Unplug USB Flash drive from PC and reboot computer.
  10. On restart, on prompt to enter password, use 'se' (without quotes)
  11. When program launched, verify that new settings are programmed. Refer to the "Copy Configurations between EPS320 computers" document. (Available to distributors and agents only. Register to gain access or login to obtain the document.)

Q: What should I do if I want to save the EPS320 Cardiac Stimulator custom settings to an external medium for safe keeping?

A: Refer to "I want to copy EPS320 Stimulator Configuration" FAQ above and store the Flash Drive, you can use it to restore the settings on the Source machine at a later date.

Q: What should I do if I would like to decrement multiple Sx simultaneously in the Multi_Sx protocol, e.g. S2, S3 and S4?

A: Software Ver 3.20 can auto-decrement only one Sx at a time. A workaround exists using the Macro Utility which can store key presses and play them back:

Macro programming steps for decrementing S2-S4:

To recall Macro: F6

Q: What should I do if I would like to decrement Sx other than the highest disabled Sx?

A: Highlight the Sx for decrementation and press Alt-D.


System Questions

Q: What should I do if there is no ECG trace visible on EPS320 Cardiac Stimulator screen although patient is connected?


  1. Select Alt-I, i.e. sense from catheter tip of paced electrode - this should always show an ECG if adequately placed in the heart.
  2. If EPS320 is using External ECG inputs, verify connection between EP recorder and EPS320 Cardiac Stimulator and verify that EP Recorder has a sensing channel selected (e,g, highlight trace and press 's' or similar).
  3. Verify that ECG is indeed connected into the ECG inputs, and not the Sync Output on the rear of the SGU.

Q:What should I do if the ECG Sensing is not triggering stimulation correctly?


  1. If there is no visible ECG trace on the EPS320 Cardiac Stimulator, refer to 'No ECG' above.
  2. Sense site possibly from wrong channel / cardiac chamber - verify that sensing is from correct EP Recorder channel and cardiac chamber.
  3. Try catheter-tip sensing (hotkey Alt-I).
  4. Some EP Recorders, e.g. older DOS version Prucka CardioLab outputs ECG from a specified displayed channel - changing Recorder 'Page' may change the outputted ECG channel.

Q:What should I do if the stimulator does not pace?


  1. If High Impedance is showing, then it is always caused by a disconnection in the pacing circuit - see High impedance FAQ below.
  2. If no High Impedance, try increasing current but if no success, check measured impedance on EPS320 Cardiac Stimulator display - if < 100 Ohms, look for short in the system - also may be set to the same electrode on Stim Setup on EP Recorder; if impedance > 2000, look for faulty equipment in line with the stimulus circuit, eg. RF Ablation switch box.
  3. Connect Test LED (MP3058) to the Stimulus Connection Box and verify that EPS320 Cardiac Stimulator functions OK.

Q:What should I do if high impedance message is observed when pacing?

A:  This indicates disconnection in the pacing circuit external to the stimulator - it is not a EPS320 Cardiac Stimulator fault. Ninety-nine percent of time high impedance is caused by incorrect settings in the EP recorder, ie Stim channel not enabled or directed into channels with no catheter connected. Other times it is caused by disconnected or broken catheter.

  1. Check that Stim channel is enabled on EP Recorder and correct electrodes for stimulation are programmed.
  2. Verify that electrodes are connected into correct catheter input module.
  3. Check continuity of pacing catheters, replace catheters if open circuit found. NB: continuity may be checked by demonstrating presence of stimulus at a particular site with the Test LEDs supplied by Micropace.
  4. Connect Test LED (MP3058) to the Catheter Input Module Stimulus Bypass Outputs and verify that stim circuit is intact to the input of the EP Recorder - if OK, then circuit break must be in EP Recorder or its Catheter Input Module / catheters.
  5. Connect Test LED (MP3058) to the EPS320 Stimulus Connection Box (MP3014) or SM-Box and verify that EPS320 Cardiac Stimulator cabling is intact up to that point.
  6. High impedance. It means that the resistance in the pacing circuit is too high - and pacing current is not being delivered. It does NOT usually mean a fault in the stimulator.

90% of time high impedance is due to incorrect settings in the CardioLab - ie Stim channel not switched on, or directed into channels with no catheter connected. Rest of the time it is caused by disconnected catheter or broken catheter.

This is thus a very helpful feature in diagnosing cause of failure to capture pacing.

Q:What should I do if I am getting noise on the stimulated EP Recorder channel?

A: This (50Hz noise) may occur especially when EPS320 Cardiac Stimulator is installed remotely from patient (in the control room) with a long Stimulus Extension Cable in between or when other equipment is connected into the pacing circuit such as RF Ablators or 3D Mapping system.

We suggest you first connect pacing electrodes directly to the EP Recorder Catheter Input Module Stimulus Bypass outputs:

  1. If noise persists then it is probably being induced in the Stimulus Extension Cable and you should check all cable connections and ensure cable is away from interference such as computer monitors and it is laid in a non-conductive conduit away from noisy cables.
  2. If noise resolves, then it is being induced in the EP Recorder or attached equipment - remove these one by one.

If noise intractable, EPS320 Cardiac Stimulator system may be split, locating the Stimulus Generator Unit under the bed, joined to the Bona PC via an RS232 cable.

Q:What should I do if I am getting large stimulus spikes on paced IECG channel?

A: Large stimulus spikes may occur with high stimulation currents, unipolar pacing or high impedance is pacing circuit. Check your settings and adjusting the clip on the EP Recorder channel may resolve the problem.

If you are getting high impedance warning and not capturing myocardium as well, then you have a break in one only of the +ve or -ve legs of the stimulation circuit. The remaining one connected circuit leg conveys a maximal voltage (almost 30V) to the myocardium trying to deliver the programmed current, but there is no return pathway for the current so none flows but a large spike is produced on the EP recorder. Correct this by rectifying broken circuit.

To locate the circuit break, connect pacing electrodes to the EP Recorder Catheter Input Module Stimulus Bypass outputs - if this rectifies problem then break is in connection between the stimulator and the EP Recorder Stim inputs; rarely the stimulator itself is faulty.

There have been unconfirmed reports of intermittent stimulus circuit interruption in EP Recorders, suspected to be related to concurrent use of 3D mapping devices.

Q:What should I do if I am getting a secondary spike on the stimulus artefact in the HRA channel and it looks a little like a capture?

A: This may occur with earlier EPS320 Cardiac Stimulator systems when used with GE CardioLab System. An upgrade to the EPS320 Stimulus Generator Unit resolves this issue. Contact Micropace.

Q:What should I do if the EPS320 Touch Screen occasionally freezes?

A: This was due to a third party driver fault in software version 3.20.05, shipped from April 2005 to Dec 2005. Computer freeze occurs rarely and randomly on touching the touch screen anywhere. Stimulus Generator Unit enters Manual Backup mode, ready for emergency stimulation if required; product performance degradation causes no hazards. Rebooting computer recovers computer function.

More that 90% of affected software has been electively field-upgraded to 3.20.09 (SR3) between March 2005 and Nov 2005.

Workaround - use keyboard only and call Micropace for software upgrade which is performed on site via a USB Flash Drive.

Q:What should I do if I am getting noise on the EPS320 Cardiac Stimulator ECG trace?

A: Assuming noise is the commonest 50Hz - the circuit is picking up 50Hz - either being injected by some third party equipment or due to unbalancing of the stim outputs - unequal resistance in connections or selective grounding of the +ve or -ve wires in the Stim circuit.

You will need to determine more information and then contact your distributor or Micropace with it:

Questions / Suggestions:

  1. Is this new noise in an existing Micropace installation or a new installation?
  2. Describe installation - stim extension cable used ? - Micropace or custom made there? How long roughly (2m , 10m. 20m)?
  3. Have they added any new equipment recently to the circuit - RF ablator, mapping system?
  4. Check all connection - disconnect and reconnect all connectors? Fixed noise?
  5. Swap channels - use Chan 2 Ventric to pace - if noise remains - must be wiring, if it disappears, must be Stimulus Generator - Chan A.
  6. Use Bypass pacing outputs - if noise disappears could be in STAMP (unlikely)
  7. What is the pacing impedance shown on the Micropace EPS320 Cardiac Stimulator?
    Try bypassing the personality module of the RF Ablator.



System Features Questions

Q: Can I use the INHIBITED mode Pacing as backup pacing during procedures likely to produce baradycardia or asystole?

A: It is possible, however, you must bear in mind:

- INHIBITED mode has no noise reversion to VVI (as pacemakers do) and so any noise, such as from RFA, can simulate ECG (oversense ECG), causing stimulator to fail to backup pace asystole, leading to patient harm. If you expect profound or permanent bradycardia during a procedure, you should of course closely monitor the patient ECG and be ready to start pacing when needed and not rely on stimulator to make that decision, and in case of stimulator malfunction, be ready to pace patient using a temporary external pacemaker (TPM).

- EPS320 is a diagnostic stimulator and not designed for, nor approved for life support pacing - it should not be used as such. Users should use temporary external pacemaker (TPM) for life support.

Q: What is Inhibited Mode pacing intended for?

A: Inhibited Mode pacing may be used for

- Conditional delivery of S1 stimuli during Multi_Sx stimulation for VT Induction, so that premature ventricular beats reset the S1 interval and preserve the conditioning train.

- 'Backup' pacing to maintain smooth heart rate during procedures expected to produce dropped beats or bradycardia in order to prevent the altered cardiac contraction rhythm from displacing the ablation device from the target area. This may include AV Nodal ablation. HOWEVER, user must bear in mind that  INHIBITED mode has no noise reversion to VVI (as pacemakers do) and so any noise, such as from RFA, can simulate /oversense ECG causing stimulator to fail to backup pace asystole, leading to patient harm.

- In any case, EPS320 is a diagnostic stimulator not designed for, nor approved for life support pacing - it should not be used as such. Users should use temporary external pacemaker (TPM) for life support at all times.

- Refer to Training Videos in Clinical Training

Q: What should I do if the ECG on our stimulator disappears when we pace?

A: If ECG disappears during pacing and then returns after a few seconds then you are probably sensing internally in the stimulator from the paced electrodes - ie Catheter Tip and the disappearance is due to charge build up on the paced bipole.

To correct this, change to external ECG sensing by pressing 'Alt-1' on the EPS320 to sense from its EXT_ECG1 input and connect your EP Recorder's ECG output (usually a BNC connector labelled 'Analogue Out' or similar) to the EPS320 "ECG-1 INPUT" on the rear of the Stimulus Generator Unit (MP3008), suitable cable BNC to Phone Cable - MP3109. Don't forget to press 'Alt-S' to save setting.

If the ECG signal disappears when you change pacing channel on the stimulator, your sensing is probably from Auto-Ext whereby sensing is from External ECG-1 INPUT when pacing Chan1 and automatically changes to ECG-2 INPUT when pacing Chan 2. To correct this, press 'Alt-1' to set sensing permanently from ECG-1 INPUT. Don't forget to press 'Alt-S' to save setting.

To learn more - on the EPS320 press 'H' for help and select "b.ECG Sensing Diagram".

Q: What should I do if I want to set the Trigger-S1 delay to be adaptive to sensed RR?

A: The Trigger-S1 delay in the EPS320 is called QRS_Sync_Delay and may be set to the S1 value, an absolute ms value or to a percentage of the sensed RR interval. It is controlled by the Config Var 33 "QRS Sync Dly:0,1-99,>100". Here is its help text:

Var_33. QRS Sync Delay:

  1. Stimulator waits this long AFTER detection of QRS before starting to pace; i.e. pacing will not commence until either -

    a. QRS is detected followed by a delay set by variable 'QRS_Sync_delay' in Config. Different values of this variable are interpreted differently as shown here below:

    0: Delay equals the setting of S1 in ms units.
    1-99%: % of RR. Delay derived from a percentage of average RR (adaptively exponentially filtered).
    >=100ms: Absolute delay in ms.
    (-1 to -99: 'Back door' way to set delay to 1ms to 99ms, in case this is ever required - see below on how to enter -ve values)
    Default value is 0.


    b. If no QRS is detected, timeout set by QRS_Sync_Timeout in Config (default=1000ms).

    E.g. if ECG RR interval is 800ms, and QRS_Sync_Delay value is 70, then pacing will commence 800 x 70%= 560ms after detection of QRS.

  2. This time period adds to QRS_Sync_Timeout period if no QRS is detected.

Q: What should I do if I want to disable PAUSE in the Nodal ERP protocol so S2 is followed by next S1?

A: You can 'turn off' PAUSE by setting its value to 'Pause=S1'. Do this by focusing PAUSE, pressing INS and choosing this value from the menu.

Q: What should I do if I want to deliver successive trains of 15 S1's starting at 250ms, reducing by 10ms each time?

A: Your task can be archived with Load-ATP:

  1. Press 'L'.
  2. Highlight Percent (Green) and press DEL (to turn off adaptive S1 calculation)
  3. Set S1 to required starting S1 value
  4. Set Train to 15
  5. Set Decr to 10
  6. Set PAUSE to required pause and ensure it is set to Repeat
  7. Start pacing

Q: Can I sense from one channel and pace into another?

A: Yes - this means triggered pacing mode - e.g. sense Atrium, delay and pace Ventricle - this can be set up easily using Procedure Menu - Triggered pacing.

Q: Can the EPS320 be used for Oesophageal Pacing?

A: Yes, The EP320 Cardiac Stimulator is intended to be used for diagnostic electrical stimulation of the heart for the purpose of initiation and termination of tachyarrhythmias, refractory measurements and measurements of electrical conduction. Stimulation may be endocardial, epicardial or trans-esophageal.

Oesophageal stimulation typically requires longer pulse widths of 10-20ms for lowest pacing thresholds of 5 to 15mA. The EPS320 features a maximum pulse width of 10ms and maximum stimulation current of 25mA. Micropace has anecdotal evidence of successful use of the EPS320 for oesophageal stimulation. Please contact Micropace for further information.

Q: Can the EPS320 Cardiac Stimulator be used for high frequency stimulation of intra-cardiac Vagal Ganglia?

A: The EPS320 Cardiac Stimulator's intended use and indications for use do not include stimulation of nerve or autonomic ganglii and there are no safety or efficacy data for this application, however there are no known contra-indications or hazards to the stimulation of any part of the heart using its full range of stimulation parameters.

High Freq Vagal Ganglion stimulation has been performed in a number of centres with the EPS320 Cardiac Stimulator.

Studies using various types of cardiac or nerve stimulators, including the EPS320 Cardiac Stimulator used typically S1=50ms (20 Hz), Pulse Duration 5-10ms, Current 3-15mA (which = 3-15V assuming typical impedance 1 kOhm).

Q: How do I instantly increase stimulation current to be able to do para-hissian pacing?

A: In para-hissian pacing, some protocols require changing stimulation current from small to large value and back again from stimulus to stimulus.

Use following steps:

  1. Focus the 'Current' parameter by touching it or pressing 'C'
  2. Set the low value of current and start pacing
  3. Press Ctrl-INS to increase stimulus current to 20mA instantly
  4. Press Ctrl-DEL to revert the stimulus Current to previous (low) value

Note that S1 and extra-stimulus current values are also independently programmable from the Joined-Chan Menu ('J').

Q: How can I make the SNRT protocol stop automatically at the end of the period, can it then restart automatically with next S1 value?

A: Setting SNRT auto-stop:

(i) Open Configure page (hotkey 'K' and password: 'henry',
(ii) move down to Variable: 13_SNRT_Auto_Stop and set it to '1' (press 'h' for help if you want more information). SNRT will now stop at end of pacing period programmed by the Variable 14 below it.

SNRT cannot be made to restart pacing - this is intentional, as automated restarting of stimulation at say, 270ms after a 60 sec pause would not be considered safe - many thing can happen in 60 sec in the EP lab which could make such pacing inappropriate.