This virtual issue of the Journal of Sleep Research brings together a variety of articles which we have published over the last two years and which deal with new sleep technologies. The last thirty years have seen an unprecedented change in the digital world with “the web”, social media and related developments. Interestingly, with regard to the field of sleep research and sleep medicine in-house, supervised polysomnography is still the gold standard with respect to the measurement of sleep and its scoring and evaluation. Polysomnography, in short PSG, has been established for more than fifty years and usually this encompasses the eight-hour-measurement of EEG with different electrode positions, EOG, EMG and additional parameters like ECG, respiration, leg movements etc. Polysomnography involves the monitoring of sleeping subjects through audio and visual recording over a period of eight hours. This method generates and stores a wealth of data. Interestingly, in clinical practice, but also in research, only a small proportion of the data is probably used for clinical evaluation or scientific purposes. It is thus not surprising that the last ten years have seen a variety of consumer-oriented products but also the development of scientifically validated methods which aim to replace or at least compete with polysomnography. Some developers dream about home polysomnography including respiratory parameters and audiovisual recording which are then streamed during the night to a sleep lab and probably are ready for evaluation at seven o’clock in the morning with results being ready at eight o’clock. Is that feasible?

In order to consider this question, we have compiled this virtual issue of articles all proposing alternatives or new methods to replace polysomnography. At present, quite a few consumer-oriented products are on the market which claim to measure sleep and give valid results for their sleep evaluation. Probably the oldest method is actigraphy, which has been around for more than forty years. Even now many publications are based on the misunderstanding that actigraphy actually measures sleep - it does not! One of the articles in this virtual issue nicely highlights this with the title “The wrist is not the brain”. Furthermore, if you browse through the articles you will see that as Shakespeare said, “All that glitters is not gold” (from the Merchant of Venice). I have sincere hopes that our potential patients and people suffering from sleep disorders are not blinded by glossy adverts on the internet which claim that a simple device costing between 100 and 400 Euros is able to give them the full picture of their sleep. If you read through the articles you will see that this is not yet the case with all the new technology which is on offer.

I hope that the reader of these articles will get an overview of what is going on in the field of new technologies, devices and apps which claim to measure sleep and how they compare to standard polysomnography. Nevertheless, in spite of my possibly critical remarks, I do not want to discourage anybody from coming up with new methods to measure sleep at home and do this in a repetitive fashion - I think what we really need in the sleep field is to overcome the artificial situation of the sleep laboratory and furthermore move to consecutive unobtrusive measurements over periods of 7 to 14 days.  Such data could really alter our perception of sleep disorders and sleep itself.

Have fun reading these articles!

Dieter Riemann, Ph.D.

Editor in Chief, Journal of Sleep Research