ABR/ASSR Systems: EP25 and EP15

Printouts
Printouts may be configured by the user to provide anywhere from 1 to over 4 pages of information with waveforms, numerical data, latency graphs with norm data indication as well as the diagnostic report. Each page carries a header with clinic and patient data, as well as a high quality color presentation of the waveforms.

Applications
Combining portability with automatic and manual testing, the EP25 matches a wide variety of ABR needs ranging from screening to clinical testing. The automatic testing makes it well suited for waveform based screening, and the manual programmability options allow for comprehensive clinical use ranging from frequency specific threshold tests to operating room applications and cochlear implant tests. For all types of applications, the most important feature of an ABR system is the quality of the presented waveform, as this is what the diagnosis relies on. The EP25 excels in this area due to low  noise and the high quality digital technology used. 

Stand Alone Unit
The EP25 is designed as a stand alone unit, where a high quality PC is completely integrated into the unit. This allows for convenient transportation of the EP25 around a clinic, as the amount of extraneous equipment required is kept to a minimum. Ease of use and the overall quality of the ABR system, which is exemplified by the virtually complete acoustic silence of the unit, benefit from such a dedicated design. 

The Screen 
A bright and wide angle specially gold shielded screen is part of the EP25. This screen can be detached from the main unit and placed on a wall or on a separate stand. Patient communication features are also maintained in this configuration. The main unit has an additional connector for a standard monitor. 

Database
The integrated database provides a practically unlimited storage capability. 

Import / Export
Individual sessions may be exported to disk, sent through a network, or be sent by e-mail. This allows other clinics to get the data, and then import these into their own EP25 (or a normal PC with the EP25 software), and manipulate the curves with filtering etc. for in depth diagnostic examination.

Advanced Waveform Processing
After the recording is done, the EP25 still provides many tools to use, in order to optimize the waveform presentation allowing for an even deeper analysis when needed. These post recording features include the ability to change filtering, change display gain as well as time scale and to add and subtract curves. Also the ability to compare the contralaterally picked up curve with the actual curve, or to split the waveform into separate components for rarefaction stimuli and condensation stimuli enhance the ability to generate waveforms that will match the needs of the most demanding user. All of these functions are also available from any workstation when the EP25 operates in a network. EP25/EP15 Display gain, timescale, filtering etc. may be controlled after test is completed.

Medically approved – for real
The integrated design of the EP25 allows for the Medical CE mark to apply to the entire unit. This permits all formal and safety related problems arising from trying to patch together a system with PC, boards, monitor etc. to be solved elegantly and safely. The low electromagnetic noise radiation from this unit meets standards set to ensure lack of interference with other technical devices in e.g. an operating room – a natural concern with traditional patched systems. The medical approved internal power supply eliminates the need for external safety transformers. And optical isolation of all preamplifier functions, provides maximum patient safety.

Advanced PreAmplifier
The preamplifier is engineered for extreme high-quality and balanced performance. All preamplifiers contaminate the signal with additional noise. The Interacoustics Preamplifier is however so silent that it is approaching the theoretical noise limit. Also noise radiating into the system is controlled by advanced shielding, and by a common mode rejection working effectively in a wide frequency range. Such features ensure very noise free operation and makes e.g. routing of electrode leads etc. much less critical than with traditional systems. All of these features work together to provide state of the art waveforms in real life situations.

Easy Impedance Check
Impedance check is made very easy as impedance readout is provided for each individual electrode, without any need for unplugging of electrode leads.

Easy Recording
The EP25 comes with several automatic test routines already programmed into its Auto Test files. And additional Auto Tests may easily be designed by the operator. Running such automatic tests is easy, as you just need to push one button for the entire test to be executed. This also includes automatic gain setting and handling of rejection issues. It cannot be easier than that!

Manual Control
All recording parameters may be controlled manually, if needed, which is beneficial for advanced clinical use and research. Executing manual control within an automatically run session is possible, allowing great ease and yet full flexibility in conducting recording sessions.

Soft Attenuator
For testing small children this very unique feature is very helpful. The soft attenuator will ensure a gradual increase or decrease of stimulus intensity whenever the stimulus level is changed. Compared to traditional ABR units, where the stimulus comes on abruptly just like an alarm clock, the gradual stimulus increase of the soft attenuator prior to data acquisition allows the child to remain relaxed when the test starts as well as during the test.

Advanced Rejection
The EP25 operates with two rejection engines instead of one. In addition to a normal voltage based rejection engine, a second stage specialized algorithm is included, ensuring better quality waveforms than would otherwise be available.

Display Modes
Various applications call for different waveform displays. The EP25 allows all curves to be displayed on the same screen, either automatically indexed for intensity, or presented in a split screen mode with Left and Right waveforms presented separately, within the same screen. Another display option operates in the Single Curve mode, where only the curve under recording or evaluation is displayed with high display gain available for easy visual examination. Norm datamatching the patient and the recording parameters may automatically be superimposed on this display for ease of evaluation. It is always possible to customize the display for time scale, waveform positioning and display gain for all or individual waveforms if needed. Printout will then appear in accordance with all display settings – what you see is what you get. Original data is also always stored in the database to make later modification to the waveforms possible, if needed.

Normative Data
Normative data may be entered for various age groups. The EP25 comes with some examples of norm data already entered, but the clinic’s own norm data may be entered when available. The database always assures that the normative data appropriate for the patient’s age and gender are displayed when called for. 

Automatic Jewett Marks 
Push one button, and all your waveforms will have assigned suggested Jewett Marks to them! This greatly reduces the time spent per session, as patient’s waveforms falling within the norm data range will need no further work on the Jewett Mark assigning. 

Editing During Testing 
For time saving purposes it is possible to edit already obtained waveforms while the EP25 is still recording waveforms.

Integrated Report Generator 
An easy to use report generator from which you can retrieve default standard reports matching your clinics typical findings is integrated into the system. These individual reports may then be modified if needed. This system ensures that reports are done quickly, and always filed correctly within the data base for later access. The report is also available as part of the session printout. 

Patient Communication
In designing the EP25, real world applications were investigated carefully. Full patient communication was discovered to be truly needed in many real world applications, even though the technical approach of traditional systems never has allowed for such features to be integrated into the system. The EP25 has a seamlessly integrated talk forward and talk back function.

ECochG, MMN etc.
ECochG includes the ability to use short duration stimuli like click or short tone pips, as well as long duration tone bursts. A variety of electrodes (optional) may be used with the system. Marks and calculations appropriate for marking of ECochG waveforms are available. MMN is available with easy assigning of any desired stimulus paradigm and with waveform display customized for MMN. P300 and traditional cortical tests are available as well.

Cochlear Implants
The EP25 can trigger external devices designed for stimulation of cochlear implants.

Automatic Calculation of Waveform Reproducibility
To evaluate the reproducibility of any given waveform, a special recording paradigm allows a mathematical evaluation of the degree to which the waveform is reproducible. This feature is very useful in determining the quality of the recording, and can be used to automatically cease recording when the waveform has reached a quality were further recording will not benefit significantly. A great timesaver in manual as well as automatic tests.

Extensive Help Files
Drag a question mark to any button or entry field and jump right into a help file, which explains the function, gives examples for normal use, and directs you to related areas of information, if needed. Also a complete electronic operation manual with search functions is available right at your screen. These help functions are available also during recording.

Back Up
Even though the EP25 is built with quality components, it is a sound practice for data collection to back up data in the case of hardware failure, theft or contamination with viruses. An integrated back up feature allows for very easy back up, either to a network or to a recording medium like the internal CD-ROM, which may be ordered in a version that can work with CD-R or CD-RW’s (optional). 

Wall Mounted Display
The display on the EP25 can be detached from the main unit and placed on a wall. This option may in some setups allow for a very elegant and space saving solution. As the talk forward microphone is integrated into the screen itself, this helpful feature is maintained.

Upgradable with OAE
The EP25 has been designed as a platform on which other types of clinical instrumentation can be easily integrated. Taking the advantage of shared hardware and software, such upgrades are very cost effective. The Interacoustics OAE system is such an example, where the addition of a probe and some software elegantly provides TEOAE and DPOAE. Other upgrades with ENG systems etc. are also possible using the additional slots provided inside the unit.

No Batteries
To provide maximum user satisfaction, no batteries are involved anywhere in the system. This is a guarantee against the annoying (but very realistic) situation where a system suddenly degrades or simply goes down because of a drained battery.

NOAH Compatible
A NOAH module is available, allowing all data to be stored under NOAH 3.0, as well as providing full waveform processing including filtering, Jewett marking and report generation. If NOAH 3.0 is installed on EP25 itself, then all tests may be run directly from within the NOAH module.

Networks
Modern clinical settings rely more and more on electronic data handling. The EP25 is designed to work in such environments by allowing all data to be transmitted through a computer network. This allows the user to perform on-line monitoring of recordings in progress, and even control the EP25 from any of the work stations within the computer network (optional software needed). Also it is possible to use any of the work stations for subsequent waveform filtering and placement of Jewett marks, as well as writing reports etc. Monitoring and controlling the EP25 over the internet is even possible, with sufficiently fast internet services. 

EP15 for Dedicated ABR 
The EP25 is also available in a slightly downgraded version, the EP15. The EP15 is for those who needs high quality ABR testing, but not specialized clinical testing. EP15 is similar to EP25 in all aspects, including the upgrade options, but does not hold the following test options: ECochG, ML, LL, MMN, P300 and Cochlear Implant Stimulator Control. Upgrade kit (hardware and software) is available for upgrading EP15 to EP25 (optional).

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