Hera

Hera

The complex for paperless polysomnography.
(C) SMF MBN, Moscow and Charite Clinics, Humboldt University, Berlin, 1996-2000.

The system is used for recording, analyzing, and administration of EEG- and polygraphy data. The Hera was primarily made for the needs of the Sleep Medicine and offers all the advantages of a modern, digital sleep lab. The program Hera was written by Andrey Pirozhenko. Being unified with NeuroKartograph and NeuroWork into the general program-apparatus complex, the total set of neurological tasks may be completed.

The Hera is an extensive diagnostic system for clinical and scientific needs. Based on a highly efficient computer system, polysomnographic recordings and their evaluations can be made precisely and user-friendly archived.

The Hera allows to complete the recording and real time display of following data channels:

Neurological figures:
• EEG
• EOG
• EMG

Cardio-respiratory figures:
• ECG
• 3-fold flowsensor
• Respiratory effort via thoracal and abdominal movement measuring
• Snoring sound with larynx microphone
• Oxygen saturation
• Body position
• nCPAP - pressure

The setting of the channels with their amplifier parameters, critical frequencies and sampling rates (up to 1000 Hz) are individually selectable.

The system complies with the recommendations of the International Society on Sleep Studies.

Special features:
• Routine and polysomnographical derivations with up to 32 channels
• Open-system software under Windows 95/98/NT
• Signal display with highest resolution, 1600 x 1280 Pixel
• A 17"-multisynchronous monitor
• A laser printer with high-quality print-outs of the analysis results
• Reviewing possible during the recording
• Extensive neurological and cardio-respiratory analysis
• Display of the analysis results in correlation to the original data
• Results display with freely configurateable reports with Microsoft Word
• Archiving on magneto-optical disc (MOD), writeable compact disc (CD-R) or digital audio tape (DAT)

• 3D localization of the pathological activity sources in the volume of the brain. Comparison with MRT and CT images. Dipole models with 1 or 2 sources.
• Highly efficient patient data base
• Computer-controlled video system with synchronous signal recording
• Multi-operation system (with connection to network)

The Hera system software is based on the IBM-PC compatible operating systems Windows 95/98/NT.

The program functionality includes the following steps:

• Configuration of the system (definition of the channels, of recording parameters like filter values and sensitivities and the screen layout)
• Visualization of the sleep derivation on the screen in real time operation with the possibility to review during the recording
• Inspection of the sleep derivation on the screen after the recording is finished for visumanual pre-scoring
• Evaluating with the user-specifically defined parameters, either automatically or manually, as well as reclassification of the automatic analysis with extensive possibilities to edit
• Presentation of the results on the screen and print-out of reports by a laser printer like trend displays, diagrams, tabular forms
• Administration and archiving of the patient data, recording and evaluation on magneto optical disc (MOD) or writeable compact disc (CD-R)

Different functions of the system software use further Windows applications, like MS-WinWord, MS-Excel and MS-Access. The use of these well-known Microsoft programs gives the following advantages:

• The handling is easy and clear
• It is possible to work at any time with the latest version of these programs and be assured that old data will be readable (downward compatibility).

By means of this you have the best-possible data safety without abstaining to the handling comfort; and the advantages of the latest program version. A future-oriented solution for your data!

Following some features of the Hera software are explained in detail.

All night dump

Releafing

During the signal recording it is possible alternatively to

1. display the recording
• in one half of the screen in real-time while
• in the other half of the screen the signals of the already stored recording can be reviewed (i.e. it is possible to releaf the actual recording) or

2. review the actual recording by using the whole screen while real-time data recording keeps running in the background

Analysis:

Alter completing the recording, analysis can be done automatically for all recorded signals to pre-defined evaluation criteria. If is possible to start the analysis after visumanual scoring or directly after the recording is finished.

Replaying:

The display of the signals and the analysis results are shown on the display screen in two different time frames, which can be changed within wide limits. During the replaying of the recorded signals the user is able to:
• page through the whole derivation (halt-page, full-page, automatically) or to select a specific page
• change the display parameters (e.g. the definition of the channels, the signal amplitude, the filter setting, the length of a page a.s.o.)
• insert comments anywhere
• start reanalysis
• display and edit the analysis, events and / or the hypnogram
• print the particularly interesting parts
• print event and comment lists
• start the report program

Data processing:

Included in the automatic signal analysis are:
• EEG, (alpha-, beta-, delta-, theta-, wave-, spindles, K-complexes)
• EOG, (REM. NONREM)
• EMG of chin and leg, LM and PLM
• ECG, (bradycardia, tachycardia)
• Respiratory parameters (obstructive, central and mixed apnea, hypopnea, periodical respiration)
• Oxygen saturation
• Body position
• Snoring sound
• nCPAP - pressure
• Arousal detection
• Automatic drawing of a hypnogram

Editing of events:

With the visumanual scoring the user is able to mark events quickly on the corresponding signals via the mouse or a single key stroke. The events, found by the automatic analysis and marked at the corresponding signal, can be quickly reclassified or deleted.

An additional program enables the determination of a user-specific key setting for the different events.

Reporting:

The result of the manual and/or automatic analysis will be displayed by the reports. These reports can be made individually by a user-friendly report generator.

The following trend curves, diagrams, statistics and chart diagrams are available:

A. General data
• Patient data
• Recording data and montage
• User logo

B. Trend curves
• Mean respiration - and heart frequency / epoch
• Mean oxygen saturation/epoch
• Envelope curve of the snoring sounds
• Mean EMG-activities / epoch, for chin and tibialis right and left
• Delta- and Alpha share / epoch
• REM- and blinking share / epoch
• Spindles and K-complexes / epoch

C. Diagrams and charts
• Automatic hypnogram based on EEG, EOG and EMG data (according to Rechtschaffen and Kales)
• Manual hypnogram, e.g. with the stages WAKE, REM, NONREM
• Combination of Sleep e.g. with TIB, TST, WASO, SEI, latencies
• All respiratory events in correlation with the heart frequency and the oxygen saturation
• Respiratory events with reference to the body position
• Periodical leg movements overview
• Leg movements with reference to the respiration
• Event overview

D. Statistics
• Apnea- / hypopnea index in reference to TST, REM and NONREM
• Apnea- / hypopnea distribution according to type and duration
• Apnea and hypopnea interference to body position and REM / NONREM
• Mean oxygen saturation with reference to sleep stages
• Temporal and distribution in percentages of the oxygen saturation
• Desaturation and heart frequency arrhythmia in connection with apnea and hypopnea
• Mean respiratory- and heart frequency in reference to sleep stages
• Distribution of heart frequency
• Index of leg movements in reference to TST, REM and NONREM and the single sleep stages
• Number of leg movements left / right per stage
• Number of eye movements per stage
• Number and index of spindles per stage
• Number and index of K-complexes per stage

Video recording:

Optionally the Hera complex can be supplied with a video monitoring system. This can include daylight as well as infrared-light cameras. The control of the video recorder is integrated in the system software. The displaying of the video picture is possible on an external video monitor or in a window on the evaluation monitor (picture-in-picture display).

Multi-operation-system (network solution):

Multi-operation-systems can be realized by building up a network or by incorporating the system in an already existing network. By later incorporation of further recording stations and / or further workplaces the system is able to grow accordingly to the individual requirements of the Sleep Lab.

In this case all data can be transmitted from one recording station via network, and after working on them be archived centrally.

Hera supports the incorporation / building of two network types.
• Workplace-networks with a common use of resources like data carriers or printers. This type should only be used in small net works with up to 5 workplaces.
• Central-station-networks (client-server). This type is used for building a highly efficient and extensive network.