Frequently Asked Questions

General Questions

What is Physip?

Physip is a French company located in Paris, in the 11th arrondissement, that has developed innovative methods for analysing sleeping and waking brain activity using electroencephalography. We offer these methods to doctors, researchers, pharmaceutical and medical device companies to optimise their sleeping and waking analysis data.

What does ASEEGA® stand for?

ASEEGA® stands for Automatic Sleep EEG Analysis. ASEEGA® exists in 3 versions: Essentiel, Lab and Recherche. Discover here which version is best suited to your needs and uses.


How to use the Essentiel analysis report?

The analysis report is presented in the form of an Excel file, consisting of 2 tabs. The first presents an overview of the night and of the sleep parameters, and the second presents the list of waking periods to be excluded from the polygraph trace. Please be sure to print both tabs.

Why do you not offer to identify micro-waking periods to improve the polygraphy even further?

The function of the added EEG to improve ventilatory polygraphy is to identify the waking periods, similarly to the position and light sensors for example, but with greater precision. The micro-waking index is accessible only using a PSG examination.

Are the results interpreted?

Physip offers analysis results, the consistency and technical relevance of which are carefully checked, but does not offer an interpretation. The use and the interpretation of the results are entirely the responsibility of the user.

Can the ASEEGA® analysis be used for all patients?

The ASEEGA® analysis has been validated to provide help with the diagnosis of the main sleep disorders in adults – insomnia, hypersomnia, narcolepsy, OSA. It is particularly suited to the improvement of ventilatory polygraphy.

I have recorded nights using a PSG trace; can you analyse these or do you require recordings using only one EEG?

We can analyse PSG recordings, but even though we will have all of the signals at our disposal, we will only analyse the signal from a single EEG lead. In practice, we extract the relevant channel and we perform the analysis on this channel without taking into account the others.

Why do you not offer the Lab module for the PSG scoring in a medicine setting?

Essentially for practical reasons. Our analysis results are presented in the form of a report that is independent of your replay software. It is simple to report waking periods in order to exclude them from the polygraph trace. On the other hand, it would be very cumbersome to re-enter a complete hypnogram epoch by epoch (in the region of 1000 epochs in general) into the replay software. We will offer the Lab module when our results are easily importable into the replay software.

Are the results reviewed?

The analysis results are subject to a strict quality control process, but they are not reviewed by a doctor. The use and the interpretation of the results remain entirely the responsibility of the user.

Is the technology limited to nights recorded in a sleep laboratory?

ASEEGA® can analyse nights recorded both in a laboratory and in an outpatient setting.

Does ASEEGA® analyse EOG and EMG signals?

No, ASEEGA® analyses EEG signals exclusively. However, for practical purposes, if you have recorded PSG traces, you can send the entire trace and we will perform for you the extraction of the EEG channel, which we will then analyse.

Is the analysis service available to the general public?

The ASEEGA® software is intended for sleep researchers, sleep clinicians and for industrial R&D services, not for general public applications.


Are all polygraphy devices compatible?

Your device must include additional sockets to which it is possible to connect EEG electrodes. Most recent polygraphs have these sockets. Furthermore, these additional EEG sockets must be compatible with the EEG analysis.

I have several traces that have already been recorded; can you analyse these?

In principle, there is no obstacle to analysing a trace that has been recorded retrospectively, even a very long time after it was first recorded. However, you must ensure that the data fulfil the ASEEGA® specifications (location of the electrodes, sampling frequency, bandwidth, resolution).

How should I configure my device to ensure that the recorded EEG data can be analysed by ASEEGA® ?

You must find the menu allowing configurations to be performed prior to the recording, and the CzPz channel must be configured to correspond with the criteria. Please do not hesitate to contact us to find out more information about how to perform this configuration.


How reliable is the ASEEGA® automatic analysis?

We have a database of more than 500 night PSG recordings that allow us to continuously control the rigour and reliability of our work. The ASEEGA® validations have been the subject of publications in major journals. Large international research teams have put their trust in the performance of ASEEGA®.

What is special about your analysis method?

All our analysis methods share the same characteristics: they are entirely automatic, based only on the EEG and on a single EEG lead, preferably located at CzPz. Therefore, they achieve a unique compromise between performance and practicality.

Why use CzPz?

Our approach consists of simplifying the EEG, hence the choice to reduce the number of sensors used. In light of this, and in light of the work pursued by Dr Odile Benoit, CzPz has proven to be the most favourable channel. The analysis was developed and validated using this channel. Using CzPz guarantees that the highest degree of reliability can be achieved for the analysis.

How do you manage to distinguish between the waking state and REM using only the EEG?

Thanks to the implementation of high-performance signal processing methods, ASEEGA® manages to make this distinction, without using the EOG or the EMG. Concordance between visual analysis and automatic analysis is similar for REM and the waking state and for the other stages of sleep.

What experience do you have in the area of sleep analysis?

We have been developing sleeping and waking EEG analysis methods for nearly 25 years, with internationally recognised expertise in signal processing as applied to EEGs. All of our technology has been developed in close collaboration with doctors and researchers specialising in the field.

Is the ASEEGA® analysis reproducible?

Yes, ASEEGA® is 100% reproducible: A same single trace analysed twice by ASEEGA® will produce exactly the same result.

What scoring rules are used by ASEEGA® ?

ASEEGA® uses classification recommended by the AASM, using 5 different stages, 4 sleep stages and wake. The sleep onset definition, which is necessary to calculate many sleep parameters, follows the AASM rule. Other classifications and sleep onset definitions are available on demand.

Technical questions

In what form should the data reach you in order to be analysed?

ASEEGA® analyses files in the edf format. In the context of research studies, we can also read certain original formats: please get in touch.

Are there any exclusion criteria for the traces?

The traces must comply with the ASEEGA®, specifications, in terms of duration, sampling frequency, amplitude resolution and bandwidth. For more details regarding the specifications for the recordings and the continuation of the polysomnographs and polygraphs, see here.

What format are the results provided in?

Pdf reports are available. Results are provided as Excel reports, Matlab structure or XML files.

How can I convert my traces to the edf format?

Most of the current polygraphs and polysomnographs provide the option to export recording files in the edf format. Please get in touch with us or with your usual partner if you need help to perform this operation.

What happens if I send traces that do not fulfil these criteria?

Two scenarios: If you have subscribed to the “security” option, then you will not be charged for any non-compliant traces you send us. If you have subscribed to the “independence” option, then you will be charged for all the traces sent, even the non-compliant files that may have escaped your notice.

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Physip S.A

6 rue Gobert – 75011 Paris
+33 (0)1 42 17 00 10

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