We have compiled a list of frequently asked questions (FAQs) to assist you in quickly locating the information you need.  Please click on the question to view the corresponding answer.

General Recorder:

Do I have to use NorthEast Monitoring flashcards in the recorder, and can I use SDHC flashcards in my DR200 and DR181 recorders?

Flashcards from other vendors may be used in the recorders; however, because some commercial-grade SDHC cards draw too much battery current resulting in short recordings, we recommend one of the following:

1. Use SD cards supplied by NorthEast Monitoring for Holter recording, especially for recording greater than 48 hours in the DR200 recorders. (The DR180+ recorders use compact flashcards (CF) and the DR200 and DR181 recorders use SD or SDHC flashcards.)

2. Use Industrial Grade memory cards that draw less than 50mA at 2.7V during any phase of operation, including write cycles. Because of the unreliability of the commercial SDHC cards now on the market, Northeast now supplies Industrial Grade SD Cards (512 MB) that are tested to insure they comply with this requirement. This is a very difficult measurement to make. If you choose to purchase SD or SDHC cards on your own, we recommend you do the following:

  • verify the cards meet this specification in the documentation of the device and/or with the manufacturer
  • test the cards to see if they meet this specification
  • test each card you plan to use in a patient study at least once, for a greater amount of time than the expected recording time. Before using a new flashcard, format the card using Initialize Flashcard in the Holter program. Often, after a flashcard is used a few times, the card may “adjust” its memory map so that high-current write cycles no longer occur.
Holter LX Analysis considerations

Older versions of the recorder and Holter LX Analysis software also have an effect on what cards you can use. For the DR181, only those with firmware v3.04 and later are able to use SDHC flashcards, and for the DR200, firmware v1.11 in the DR200/E and v4.21 in the DR200/HE and later can use SDHC. The Holter Analysis software 5.4D and later is able to read all cards, however, earlier versions of the software can only read cards that are less than or equal to 2 GB.

Card reader considerations

Some older (pre-2014) card readers do not recognize SDHC cards, so if you cannot “see” your flashcard using Holter Analysis or Windows Explorer, that may be the reason.

Why is my recorder stopping before it should?

The shortened recording times may occur because the Holter is shutting down due to a depleted battery. One cause of premature battery depletion is flashcards that draw too much current in the DR200 recorders. Refer to to the Answer to Question 1 above for more information regarding flashcards.

Why am a getting a "Memory Full" error message and a short recording?

The patient’s Holter data is stored in the recorder on a removable flashcard. Be sure to select the correct format and size when using the Initialize Flashcard screen in Holter. If you sometimes do recordings that are more than 48 hours, choose the 14-day or whole card option.

Also, be sure to allow the initialization process to complete before removing the flashcard from the reader. In normal mode, to store 24 hours, 28 megabytes (MB) is required; and for 14 days, 390 MB. Higher resolution recordings require 2 times the amount as normal mode.

To view the actual size of the flash.dat file on your card, put the card in the reader and view the file when prompted or through Explorer. If you have enough capacity on your SD card, but are getting short recordings, the flash.dat file on your flashcard may have been corrupted. You can fix this problem by reformatting and re-initializing your card. Refer to the software manual, under “Initializing a flashcard”, for more information.

When should I replace a cable?

A problem with your recordings may be the result of a cable that is not functioning properly because it is damaged or old. First check to see if you cable is damaged or badly worn. If so, it should be replaced. Even if the cable appears to be fine, a cable that needs replacing may result in one or more of the following issues: poor quality hook-ups – any or all channels are artifact , low voltage QRS, or lead quality test always below 3.

How do I care for the cable?

Keep your cable in good working order for as long as possible by caring for it as follows:

  • Don’t bend or wrap wires around recorder
  • Clean leads between uses with metricide or bleach
  • Make sure electrodes are new and kept at right temperature. Not dried out or rusted
  • Check cable for breakage between uses.

What do I do when the recorder keeps counting and won’t begin recording?

Remove and initlalize the card using the Holter program and reinsert. If this does not solve the problem, please call your dealer or NorthEast Technical support for further troubleshooting or an RMA number.

What do I do when the recorder will not boot up or start after new batteries are inserted?

Call for an RMA so you can return the recorder to be repaired.

How do I return broken equipment?

An RMA is required to return broken equipment. Contact your dealer or NorthEast Technical Support for an RMA number and instructions on returning.

I have a Holter unit from NorthEast (direct, via Rozinn, Welch Allyn, etc.) and when it starts up it gives me the version number of the firmware built into the recorder. Can I get the latest firmware version without returning the unit?

If you have a DR180, DR180+ or RZ153, you’ll need to return the unit to our Channel Partner (dealer / distributor) or directly to NorthEast for this update. The version current at the time this FAQ was written (May 2007) is v2.14. If you have a DR200, it is possible that the firmware can be updated “in the field” by inserting a special SD flash data card with the update on it. Please contact your nearest Channel Partner or NorthEast directly to discuss anupdate.

I am using a Windows 10 machine and I am getting the message “No card or flash.dat file in recorder” after initializing the SD card. A flash.dat file is visible when I look at the card using Windows Explorer. What should I do?

Sometimes Windows 10 machines modify the SD Card so that the flash.dat file cannot be recognized by the Holter recorder. In order to fix this moving forward, you will need to:

  1. Reformat the SD card using a utility called SD Formatter, which can be found here. After downloading and installing The SD Formatter for Windows, you will need to format your SD card before using the Initialization screen in the Holter Software. Administrative privileges are required to run SD Formatter.
  2.  Initialize the reformatted card using a new Initialize program which can be found here. The new Initialize program will run from the Holter software once installed. The new Initialize program will not be able to change the size of the flash.dat file as per the screen. To change the size of the flash.dat, you will need to use SD Formatter to format the card before running the Initialize program with the new file size. If the SD Card becomes unusable again, you can use the SD Formatter before initializing the card again.

If the SD Card becomes unusable again, you can use the SD Formatter before initializing the card again.

DR181 Holter Recorder:

Is the DR181 compatible with earlier versions of LX Analysis and what about accessories?

The new DR181 in 3 channel recording mode is compatible with v5.2 or newer version of Holter LX Analysis. (This is the same as the DR200/HE units.)

The DR181 in either OxyHolter (this includes analysis for OSA, i.e., Sleep) or the 12-lead mode requires v5.4b or newer version of Holter LX Analysis.

All cables (Holter 5-, 7- and 12-lead, OxyHolter and OxyHolter/A) that are in the field AND are working with DR180+, will also work with the DR181.

The only difference in hardware between the DR180+ and the new DR181, is that the DR181 uses an SD card instead of a CF card.

In Holter LX Analysis, what should I choose to initialize the SD card for the DR181 recorder?

If you have an older version of the software and the DR181 is not listed, choose any DR200 option for formatting the SD flashcard for the DR181.

How do I remove the SD flashcard from the DR181 recorder?

Gently press inward on the SD card to release. The card should pop-out. Never pull the card out, as it may damage the recorder.

How do I change the recording mode on the DR181 recorder?

Unlike the DR180+, you change the recording mode prior to entering the patient ID. Do this by going to Settings > More > General Settings > Record Type from the main menu.

DR200 and 300 Holter and Event Recorder:

How do I remove the flash/memory card from the recorder?

Gently press inward on the SD card to release. The card should pop-out. Never pull the card out, as it may damage the recorder.

Which software should I use with my recorder?

To use the recorder in Holter mode, you MUST have some level of HE/LX or Holter LX Analysis software. The levels are Basic, Enhanced, Enhanced Plus and Pro.

If you are using the recorder in Event mode and want to transmit the data using an SD card, via LX Remote or wirelessly with the DR300 (these special modes are only available to users of our hardware and software), you must use our LX Event software.

To use the recorder in telephonic Event mode (this is the most common method of transmitting event recordings), you can use ANY event software, but using our LX Event makes life a bit easier and guarantees that the telephonically transmitted data with patient header information will be correctly / automatically received by the receiver.

Can event data that has been transferred to an SD card, be viewed with the Holter software?

Currently only LX Event can read and display an event data file that has been transferred to an SD card. If this is something that you want to do often, you may want to use the “Both” recording mode on the recorder which runs like an event, but also saves a flash.dat file that can be read using our Holter software.

How do I edit the Patient ID if I make a mistake while entering it into the recorder?

When entering the characters for the Patient ID, press the ENTER button to advance from one character to the next. If you need to backspace, hold down the ENTER key for a bit longer than normal. When you have entered the complete Patient ID, finish by pressing the EVENT button. Once you have entered the Patient ID and completed the process by pressing and holding the EVENT button, the only way to change the Patient ID is to remove the battery and start over again. See, “To Start the Recorder for Holter”, on the handy Hookup Guide.

The recorder keeps displaying a “Lead Loose” message?

Electrodes that are dried out will cause this message to appear and should be replaced. However, some types of electrodes, including the new, high-impedance gel formulations, cause the “Lead Loose” message to be displayed even though there is not an issue with the signal quality. If you are receiving an adequate signal, you can turn the “Lead Loose” message off under “Settings.”

How do I switch the DR200/HE or DR300 recorder from Event to Holter recording?

After deleting the events by pressing either arrow for 3 seconds, reboot the recorder by removing and reinserting the battery. Then, interrupt the 15-second countdown by pressing ENTER, down arrow, up arrow and the EVENT button. Now press ENTER and go to the General Settings menu where you can change the recording type from Event to Holter.

General Holter:

How do I install the software?

An installation instruction sheet was included in your software package or can be found on the back of the Disk box. If you encounter problems or have questions with the installation process, call your dealer or NorthEast Technical Support for assistance.

How can I customize the software?

Refer to the manual for instructions on how to customize the software using the Configurations and Preferences features.

How can I get more training on using the software?

NorthEast offers three types of customized training to meet your organization’s needs: On-site training, Off-site training, and Internet training. Please call NorthEast Sales or Technical Support for more information regarding training options and pricing.

How do I change the software to an alternate language?

For HE/LX Analysis you can update the language in the HE-LX Analysis Settings screen found under “NorthEast Monitoring” in your Windows Program list.
In order to set up an alternate language in Holter LX Analysis, you will need to do the following:

  1. Install software on your desktop. Allow it to complete the first installation in English.
  2. Return to the Utilities screen and change the language to what you desire.
    At this point all of the lists, screens and standard configurations will be updated to the new language.

Why do I sometimes see other languages on the screens when using the Holter software?

The alternate language feature of the software may not always work correctly if the language you select for the Holter softwae and the language of your PC’s operating system are not the same. This should not be a problem when the two languages are identical or if your PC’s operating system is set to “English.”

How often should I Archive or Back up up my Holter data?

Archiving or backing-up your data to another driectory should be done on a regular basis as determined by your organization.

Help, I am having problems initializing the SD and/or compact flashcard on my computer!

it may have to do with an interaction between the Holter software and Windows, and the most likely cause of initialization/erase card errors are either selecting the wrong type of initialization or removing the card from the reader before the initialization process is complete. In order to repair, see attached pdf file for instructions.

What should I do when I get the message, “Flash file not found” on my computer?

First make sure that the card reader is plugged in and that a card is inserted correctly into the reader. Second, it may be that your computer can no longer see your Card Reader. To fix this, remove card reader plug from the computer and plug into a different USB port on the computer. Third, try turning off and restarting your computer. If you still cannot see the Flash file, your reader may be defective. Try using another reader if available, or call your dealer or NorthEast Technical Support for further assistance.

How can I adjust the period over which the software operates in order to eliminate data during portions of the study?

There are a couple of ways to adjust the time period over which the software operates. It is possible to alter what is analyzed by two methods. 1) First, you can go to the TREND screen, then drag the cursor across the region you want to exclude, label it ARTIFACT by clicking on the ARTIFACT button. Repeat as necessary to eliminate multiple regions in the study. 2) A second approach eliminates all time after a designated point. Identify the time that you would like the analysis to end by placing the cursor at that point on either the TREND or PAGE screens. Then from the toolbar, select Review > Shorten Analysis Time.

What should I do when the software identifies pauses that are not real?

If the QRS complexes are very small, some of them can be missed so that the software identifies false positive pauses. If that happens, go to Review > Calibration, move the calibration lines as close to the baseline as possible, and press Done. The software will reanalyze the signal using a higher gain and find the small QRS complexes.

My patient is in atrial fib. How can I relabel all the SVPBS that were counted?

If the patient is in atrial fibrillation throughout the entire recording (look through the signal in the Page window to verify this), in PRO and Enhanced Plus, you can go to Trends, drag your cursor across the entire histogram, click on the Afib On button on the toolbar, and then do a Review>Update. If you are using Basic or Enhanced, you can disable SVPBs in the Settings>Scanning Criteria screen, but this will reanalyze the ECG from the beginning and you will need to start your review over.

How can I quickly re-label incorrectly labeled pacemaker failures?

In Critical Events, select Sense Failure, then drag across all the bars in the histogram at the top of the window; they should turn magenta. Press the Q button to re-label all the examples Questionable/Unknown. Do the same for Capture Failure. Then, still in Critical Events, go to Questionable and drag across the histogram again; this time, press the “P” button to re-label all the examples Paced. They are now counted as paced beats, but not pacemaker failures.

I have a study where many T-waves were categorized as PVBs. Why did that happen and how is it best handled?

We expect the T-wave detections were caused by a slightly long period, from the R-wave to the apex of the T-wave (not to the end of T) and low R-wave amplitude. In cases where there is no clean channel and with an R-wave larger than the T-wave, the best thing to do is generally to increase the “extra dead time”. This adds to the refractory time during the normal T-wave period where an R-wave detection is not possible. While the program attempts to adjust this time as a function of heart rate, sometimes it is necessary to increase the Extra Dead Time value directly.

Extra Dead Time can be changed in Settings -> Scanning Criteria. Normally it is set to 0.06 but try changing it to 0.10 or even 0.15. The maximum value the program will accept is 0.30. If your Settings in the Scanning Criteria allow for two channel processing, it will use the Primary and Secondary Channels specified in the Scanning Criteria. Normally the Primary Channel is used for R-wave detection and the Secondary Channel is used in the case of a possible missed R-wave. Both channels are used for morphology and artifact measurements.

HE/LX Analysis Software:

Does the HE/LX Analysis software require certain versions of Java?

No, you do not need a stand-alone version of Java in order to run the HE/LX Analysis software.

On what operating systems can I run the HE/LX Analysis software?

the software has been tested to run on Windows 7, 8 and 10. If you encounter issues installing your software, please contact NorthEast Technical Support for assistance.

Holter LX Analysis Software:

Does Holter LX Analysis require certain versions of Java?

At the time of writing this FAQ, the most recent version of Java is 1.6.0. Although it is officially still a “beta” version, it has been thoroughly tested with LX Analysis and is available from the Sun Microsystems web site.

You can check your version of Java by typing the following at the DOS shell command prompt: >java -version. Here is what we get in response to this command:

  • java version “1.6.0_03” Java(TM) SE Runtime Environment (build 1.6.0_03-b05) Java HotSpot(TM) Client VM (build 1.6.0_03-b05, mixed mode, sharing).

Holter LX Analysis v5.3 requires Java 1.6.0 or higher. Holter LX Analysis v5.0, v5.1 and v5.2 requires Java 1.4.2 or higher. However, we are aware of a problem with Java 1.6.0 and Holter LX Analysis v5.0 & v5.1. These older versions of Holter LX Analysis do not work properly with the latest Java 1.6.0. The easiest solution to this problem is to update Holter LX Analysis to at least v5.2 and preferably to the latest version which is v5.3. If it is important to maintain the use of these Holter LX Analysis v5.0 or v5.1, there are a few options.

Do not update from the older versions of Java on the computer that runs Holter LX Analysis v5.0 or v5.1. If you are required to update to a newer version of Java for an application other than Holter LX Analysis, there are options:

  1. Maintain separate computers for the two applications that require different versions of Java.
  2. Carefully manage the environment variable JAVA_HOME and PATH when running either of the two applications that require different versions of Java.
    In theory one can install two versions of Java on the same machine and switch which version is being used for a given application. We have never tested this and have no further details on how to do it, except to say that it involves a change to the environment variable JAVA_HOME and the entry in the PATH variable just before running an application, you can change which version of java is being used. This can still be a problem if it is necessary to run both applications at the same time. One would have to open each one in a separate command shell. Again, we have not tried any of this so we don’t have working samples of commands to do it.

On what operating systems can I run the Holter LX Analysis software?

Software version 5.4 has been tested to run on XP and Windows 7 operating systems, and Windows 8 as of 5.4E. Version 5.3 has been tested to run on XP and Vista operating systems. Version 5.2 has been tested to run on XP, although we have found that it can also run on Vista systems. If you encounter issues installing your software, please contact NorthEast Technical Support for assistance.

After installing software from NorthEast, including the new Sentinel drivers, I now get an error when I start up my computer that refers to a "Sentinel Protection Server to SuperPro and UltraPro network keys"? How do I fix this?

After installing the Sentinel drivers, do the following:Start up the Windows “Control Panel” (on my system it is, Start -> Control Panel, while on other systems it might be something like, Start -> Settings -> Control Panel). When in the Control Panel, go to Administrative Tools -> Services. Scroll down to and highlight the selection for the Sentinel Protection Server. Right click on the Sentinel Protection Server and select Properties. Set the Startup type to “Manual” (as opposed to Automatic or Disabled). Click on Apply and then exit from the tools.

LX Event Software:

What is the structure of the files and/or database used in LX Event?

There is a “database” file called “NMPatients.ndb” that has the search keys for the “FIND” frame. It also has the path to the data files. This is an ASCII file. In the directories with the actual patient data pointed to by this key file is the raw data. This is in the form of a ActiveProcedure.npe file, backups and the raw phone.wav files. The .npe file is also an ASCII file with the raw data included as a readable, but hex, line of data.

What support is there for an HL7 interface from LX Event to a Hospital Information System (HIS)?

The lack of a true, generic HL7 standard is problematic for medical software developers. Without a generic standard, it is difficult to write a supportable interface to an HIS (Hospital Information System). License issues for the interconnection to the HIS are also a difficult issue. However with the proper “hooks” into the application, in many cases it is a relatively easy task to customize an interface and accomplish the desired result.

Given a need to create an interface to an HIS, here are the basic considerations. If these parameters are provided, we can usually provide an interface to accomplish it:

  1. Exactly what pieces of information in the text portion of the LX Event report should be made available to the HIS?
  2. How, if at all, would the waveforms be passed in? Typically this is the most significant problem and is often solved by just passing in the whole PDF report file.
  3. Is it required that any information be passed from the HIS to LX Event to enter a new patient? This is often the most difficult part to set up. In practice it does not get done because so little information is really passed in this direction – usually only the patient name, address, ID and physician name – and the effort is so great to accomplish this.

Frequently, the most sensible approach is that once the the information needed by the HIS system specified (see question 1 above), NEMon can extract that information and place it in a defined file/location. From that point, an IT specialist at the HIS-end, generates the interface to pick up and insert the data into the HIS. This solves the licensing issues and assures a supportable product. For example, in our Holter software product, Holter LX Analysis, we have mostly solved this issue. We provide an optional output file generator for users. It creates an output file which is a simple ascii, XML-like format. It includes all information from the report which is not graphic in nature and is not in a repeating table. Only the summaries of tables are included. This still requires that an interface be generated locally at the HIS-end to read this data into the HIS system.

One or more users are unable to print using LX Event 2.11. How can I fix this?

The LX Event printing program has a printing failure mode which occurs when it is run under a user who did not intially do the installation. In order to fix this, each LX Event user will need to have the following lines, which are all”string value”, added to their registry:


We have created a file to do this for you – nemonpdf_current.reg. In order to run this, the system must be logged in as the intended user. When logged in as the user, click on this file and let the system open it in regedit. It will ask for permission a number of times. All anti-virus programs will treat this as a significant threat. It may take some effort to make the system permit its use.

If this is a single user installation, you may choose instead to un-install the nemopn-pdf program and LX Event. Then re-install it being logged in as the intended user. The LX Event program installer should then make the required registry entries.

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